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Amino Acids, Peptides, and Proteins

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Articles 1 - 30 of 142

Full-Text Articles in Cell Biology

Leptin Promotes Expression Of Emt-Related Transcription Factors And Invasion In A Src And Fak-Dependent Pathway In Mcf10a Mammary Epithelial Cells, Monserrat Olea-Flores, Miriam Zuniga-Eulogio, Arvey Tacuba-Saavedra, Magdalena Bueno-Salgado, Andrea Sanchez-Carvajal, Yovani Vargas-Santiago, Miguel A. Mendoza-Catalan, Eduardo Perez Salazar, Alejandra Garcia-Hernandez, Teresita Padilla-Benavides, Napoleon Navarro-Tito Sep 2019

Leptin Promotes Expression Of Emt-Related Transcription Factors And Invasion In A Src And Fak-Dependent Pathway In Mcf10a Mammary Epithelial Cells, Monserrat Olea-Flores, Miriam Zuniga-Eulogio, Arvey Tacuba-Saavedra, Magdalena Bueno-Salgado, Andrea Sanchez-Carvajal, Yovani Vargas-Santiago, Miguel A. Mendoza-Catalan, Eduardo Perez Salazar, Alejandra Garcia-Hernandez, Teresita Padilla-Benavides, Napoleon Navarro-Tito

Open Access Articles

Leptin is one of the main adipokines secreted in breast tissue. Leptin promotes epithelial-mesenchymal transition (EMT), cell migration and invasion in epithelial breast cells, leading to tumor progression. Although, the molecular mechanisms that underlie these events are not fully understood, the activation of different signaling pathways appears to be essential. In this sense, the effects of leptin on the activation of kinases like Src and FAK, which regulate signaling pathways that activate the EMT program, are not completely described. Therefore, we investigated the involvement of these kinases using an in vitro model for leptin-induced EMT process in the non-tumorigenic MCF10A ...


A Critical Role Of Vmp1 In Lipoprotein Secretion, Hideaki Morishita, Yan G. Zhao, Norito Tamura, Taki Nishimura, Yuki Kanda, Yuriko Sakamaki, Mitsuyo Okazaki, Dongfang Li, Noboru Mizushima Sep 2019

A Critical Role Of Vmp1 In Lipoprotein Secretion, Hideaki Morishita, Yan G. Zhao, Norito Tamura, Taki Nishimura, Yuki Kanda, Yuriko Sakamaki, Mitsuyo Okazaki, Dongfang Li, Noboru Mizushima

Open Access Articles

Lipoproteins are lipid-protein complexes that are primarily generated and secreted from the intestine, liver, and visceral endoderm and delivered to peripheral tissues. Lipoproteins, which are assembled in the endoplasmic reticulum (ER) membrane, are released into the ER lumen for secretion, but its mechanism remains largely unknown. Here, we show that the release of lipoproteins from the ER membrane requires VMP1, an ER transmembrane protein essential for autophagy and certain types of secretion. Loss of vmp1, but not other autophagy-related genes, in zebrafish causes lipoprotein accumulation in the intestine and liver. Vmp1 deficiency in mice also leads to lipid accumulation in ...


Extensive Ribosome And Rf2 Rearrangements During Translation Termination, Egor Svidritskiy, Gabriel Demo, Anna B. Loveland, Chen Xu, Andrei A. Korostelev Sep 2019

Extensive Ribosome And Rf2 Rearrangements During Translation Termination, Egor Svidritskiy, Gabriel Demo, Anna B. Loveland, Chen Xu, Andrei A. Korostelev

Open Access Articles

Protein synthesis ends when a ribosome reaches an mRNA stop codon. Release factors (RFs) decode the stop codon, hydrolyze peptidyl-tRNA to release the nascent protein, and then dissociate to allow ribosome recycling. To visualize termination by RF2, we resolved a cryo-EM ensemble of E. coli 70S*RF2 structures at up to 3.3 A in a single sample. Five structures suggest a highly dynamic termination pathway. Upon peptidyl-tRNA hydrolysis, the CCA end of deacyl-tRNA departs from the peptidyl transferase center. The catalytic GGQ loop of RF2 is rearranged into a long beta-hairpin that plugs the peptide tunnel, biasing a nascent ...


Expression Of Mitochondrial Membrane-Linked Sab Determines Severity Of Sex-Dependent Acute Liver Injury, Sanda Win, Robert W. M. Min, Christopher Q. Chen, Jun Zhang, Yibu Chen, Meng Li, Ayako Suzuki, Manal F. Abdelmalek, Ying Wang, Mariam Aghajan, Filbert W. M. Aung, Anna Mae Diehl, Roger J. Davis, Tin A. Than, Neil Kaplowitz Sep 2019

Expression Of Mitochondrial Membrane-Linked Sab Determines Severity Of Sex-Dependent Acute Liver Injury, Sanda Win, Robert W. M. Min, Christopher Q. Chen, Jun Zhang, Yibu Chen, Meng Li, Ayako Suzuki, Manal F. Abdelmalek, Ying Wang, Mariam Aghajan, Filbert W. M. Aung, Anna Mae Diehl, Roger J. Davis, Tin A. Than, Neil Kaplowitz

University of Massachusetts Medical School Faculty Publications

SAB is an outer membrane docking protein for JNK mediated impaired mitochondrial function. Deletion of Sab in hepatocytes inhibits sustained JNK activation and cell death. Current work demonstrated that increasing SAB enhanced the severity of APAP liver injury. Female mice were resistant to liver injury and exhibited markedly decreased hepatic SAB protein expression versus males. The mechanism of SAB repression involved a pathway from ERalpha to p53 expression which induced miR34a-5p. miR34a-5p targeted the Sab mRNA coding region, repressing SAB expression. Fulvestrant or p53 knockdown decreased miR34a-5p and increased SAB in females leading to increased injury from APAP and TNF ...


Diverse Repertoire Of Human Adipocyte Subtypes Develops From Transcriptionally Distinct Mesenchymal Progenitor Cells, So Yun Min, Anand Desai, Zinger Yang, Agastya Sharma, Tiffany Desouza, Ryan Genga, Alper Kucukural, Lawrence M. Lifshitz, Soren Nielsen, Camilla Scheele, Rene Maehr, Manuel Garber, Silvia Corvera Sep 2019

Diverse Repertoire Of Human Adipocyte Subtypes Develops From Transcriptionally Distinct Mesenchymal Progenitor Cells, So Yun Min, Anand Desai, Zinger Yang, Agastya Sharma, Tiffany Desouza, Ryan Genga, Alper Kucukural, Lawrence M. Lifshitz, Soren Nielsen, Camilla Scheele, Rene Maehr, Manuel Garber, Silvia Corvera

Open Access Articles

Single-cell sequencing technologies have revealed an unexpectedly broad repertoire of cells required to mediate complex functions in multicellular organisms. Despite the multiple roles of adipose tissue in maintaining systemic metabolic homeostasis, adipocytes are thought to be largely homogenous with only 2 major subtypes recognized in humans so far. Here we report the existence and characteristics of 4 distinct human adipocyte subtypes, and of their respective mesenchymal progenitors. The phenotypes of these distinct adipocyte subtypes are differentially associated with key adipose tissue functions, including thermogenesis, lipid storage, and adipokine secretion. The transcriptomic signature of "brite/beige" thermogenic adipocytes reveals mechanisms for ...


The Central Role Of The Tail In Switching Off 10s Myosin Ii Activity, Shixin Yang, Kyounghwan Lee, John L. Woodhead, Osamu Sato, Mitsuo Ikebe, Roger Craig Sep 2019

The Central Role Of The Tail In Switching Off 10s Myosin Ii Activity, Shixin Yang, Kyounghwan Lee, John L. Woodhead, Osamu Sato, Mitsuo Ikebe, Roger Craig

Radiology Publications and Presentations

Myosin II is a motor protein with two heads and an extended tail that plays an essential role in cell motility. Its active form is a polymer (myosin filament) that pulls on actin to generate motion. Its inactive form is a monomer with a compact structure (10S sedimentation coefficient), in which the tail is folded and the two heads interact with each other, inhibiting activity. This conformation is thought to function in cells as an energy-conserving form of the molecule suitable for storage as well as transport to sites of filament assembly. The mechanism of inhibition of the compact molecule ...


Role Of A 19s Proteasome Subunit- Psmd10(Gankyrin) In Neurogenesis Of Human Neuronal Progenitor Cells, Indrajit Sahu, Padma P. Nanaware, Minal Mane, Saim Wasi Mulla, Soumen Roy, Prasanna Venkatraman Aug 2019

Role Of A 19s Proteasome Subunit- Psmd10(Gankyrin) In Neurogenesis Of Human Neuronal Progenitor Cells, Indrajit Sahu, Padma P. Nanaware, Minal Mane, Saim Wasi Mulla, Soumen Roy, Prasanna Venkatraman

Open Access Articles

PSMD10(Gankyrin), a proteasome assembly chaperone, is a widely known oncoprotein which aspects many hall mark properties of cancer. However, except proteasome assembly chaperon function its role in normal cell function remains unknown. To address this issue, we induced PSMD10(Gankyrin) overexpression in HEK293 cells and the resultant large-scale changes in gene expression profile were analyzed. We constituted networks from microarray data of these differentially expressed genes and carried out extensive topological analyses. The overrecurring yet consistent theme that appeared throughout analysis using varied network metrics is that all genes and interactions identified as important would be involved in neurogenesis ...


Distinct Features Of Nucleolus-Associated Domains In Mouse Embryonic Stem Cells, Aizhan Bizhanova, Aimin Yan, Jun Yu, Lihua Julie Zhu, Paul D. Kaufman Aug 2019

Distinct Features Of Nucleolus-Associated Domains In Mouse Embryonic Stem Cells, Aizhan Bizhanova, Aimin Yan, Jun Yu, Lihua Julie Zhu, Paul D. Kaufman

University of Massachusetts Medical School Faculty Publications

Background Heterochromatin in eukaryotic interphase cells frequently localizes to the nucleolar periphery (nucleolus-associated domains, NADs) and the nuclear lamina (lamina-associated domains, LADs). Gene expression in somatic cell NADs is generally low, but NADs have not been characterized in mammalian stem cells.

Results Here, we generated the first genome-wide map of NADs in mouse embryonic stem cells (mESCs) via deep sequencing of chromatin associated with biochemically-purified nucleoli. As we had observed in mouse embryonic fibroblasts (MEFs), the large Type I subset of NADs overlaps with constitutive LADs and is enriched for features of constitutive heterochromatin, including late replication timing and low ...


Promotion Of Adipogenesis By Jmjd6 Requires The At Hook-Like Domain And Is Independent Of Its Catalytic Function, Pablo Reyes-Gutierrez, Jake W. Carrasquillo-Rodriguez, Anthony N. Imbalzano Aug 2019

Promotion Of Adipogenesis By Jmjd6 Requires The At Hook-Like Domain And Is Independent Of Its Catalytic Function, Pablo Reyes-Gutierrez, Jake W. Carrasquillo-Rodriguez, Anthony N. Imbalzano

Open Access Articles

JMJD6 is a member of the Jumonji C domain containing enzymes that demethylate and/or hydroxylate substrate proteins. It is a multi-functional protein that has been implicated in disparate aspects of transcriptional and post-transcriptional control of gene expression, including but not limited to enhancer and promoter binding, release of paused RNA polymerase II, control of splicing, and interaction with the translation machinery. JMJD6 contributes to multiple aspects of animal development, including adipogenesis modeled in culture. We mutated proposed or characterized domains in the JMJD6 protein to better understand the requirement for JMJD6 in adipogenic differentiation. Mutation of JMJD6 amino acids ...


Leptin Promotes Expression Of Emt-Related Transcription Factors And Invasion In A Src And Fak-Dependent Pathway In Mcf10a Mammary Epithelial Cells, Monserrat Olea-Flores, Miriam Zuñiga-Eulogio, Arvey Tacuba-Saavedra, Magdalena Bueno-Salgado, Andrea Sánchez-Carvajal, Yovani Vargas-Santiago, Miguel A. Mendoza-Catalán, Eduardo Pérez Salazar, Alejandra García-Hernández, Teresita Padilla-Benavides, Napoleón Navarro-Tito Aug 2019

Leptin Promotes Expression Of Emt-Related Transcription Factors And Invasion In A Src And Fak-Dependent Pathway In Mcf10a Mammary Epithelial Cells, Monserrat Olea-Flores, Miriam Zuñiga-Eulogio, Arvey Tacuba-Saavedra, Magdalena Bueno-Salgado, Andrea Sánchez-Carvajal, Yovani Vargas-Santiago, Miguel A. Mendoza-Catalán, Eduardo Pérez Salazar, Alejandra García-Hernández, Teresita Padilla-Benavides, Napoleón Navarro-Tito

University of Massachusetts Medical School Faculty Publications

Leptin is one of the main adipokines secreted in breast tissue, and has been associated with epithelial-mesenchymal transition (EMT) and tumor progression in breast cancer. Leptin promotes EMT, cell migration and invasion in epithelial breast cells, leading to tumor progression. However, the molecular mechanism that underlies these events is not fully understood; however, the activation of different signaling pathways appears to be essential. In this sense, the effect of leptin on the activation of kinases like Src and FAK, which regulate signaling pathways that activate the EMT program, has not been completely described. Therefore, we investigated the involvement of these ...


Calcineurin Broadly Regulates The Initiation Of Skeletal Muscle-Specific Gene Expression By Binding Target Promoters And Facilitating The Interaction Of The Swi/Snf Chromatin Remodeling Enzyme, Hanna Witwicka, Jumpei Nogami, Sabriya A. Syed, Kazumitsu Maehara, Teresita Padilla-Benavides, Yasuyuki Ohkawa, Anthony N. Imbalzano Jul 2019

Calcineurin Broadly Regulates The Initiation Of Skeletal Muscle-Specific Gene Expression By Binding Target Promoters And Facilitating The Interaction Of The Swi/Snf Chromatin Remodeling Enzyme, Hanna Witwicka, Jumpei Nogami, Sabriya A. Syed, Kazumitsu Maehara, Teresita Padilla-Benavides, Yasuyuki Ohkawa, Anthony N. Imbalzano

Open Access Articles

Calcineurin (Cn) is a calcium-activated serine/threonine protein phosphatase that is broadly implicated in diverse cellular processes, including the regulation of gene expression. During skeletal muscle differentiation, Cn activates the NFAT transcription factor but also promotes differentiation by counteracting the negative influences of protein kinase C beta (PKCbeta) via dephosphorylation and activation of BRG1, an enzymatic subunit of the mammalian SWI/SNF ATP-dependent chromatin remodeling enzyme. Here we identified four major temporal patterns of Cn-dependent gene expression in differentiating myoblasts and determined that Cn is broadly required for the activation of the myogenic gene expression program. Mechanistically, Cn promotes gene ...


F-Box Protein Fbxo16 Functions As A Tumor Suppressor By Attenuating Nuclear Beta-Catenin Function, Debasish Paul, Sehbanul Islam, Rajesh Kumar. Manne, U. S. Dinesh, Sunil K. Malonia, Biswanath Maity, Ramanamurthy Boppana, Srikanth Rapole, Praveen Kumar Shetty, Manas Kumar Santra Jul 2019

F-Box Protein Fbxo16 Functions As A Tumor Suppressor By Attenuating Nuclear Beta-Catenin Function, Debasish Paul, Sehbanul Islam, Rajesh Kumar. Manne, U. S. Dinesh, Sunil K. Malonia, Biswanath Maity, Ramanamurthy Boppana, Srikanth Rapole, Praveen Kumar Shetty, Manas Kumar Santra

Open Access Articles

Aberrant activation of beta-catenin has been implicated in a variety of human diseases, including cancer. In spite of significant progress, the regulation of active Wnt/beta-catenin-signaling pathways is still poorly understood. In this study, we show that F-box protein 16 (FBXO16) is a putative tumor suppressor. It is a component of the SCF (SKP1-Cullin1-F-box protein) complex, which targets the nuclear beta-catenin protein to facilitate proteasomal degradation through the 26S proteasome. FBXO16 interacts physically with the C-terminal domain of beta-catenin and promotes its lysine 48-linked polyubiquitination. In addition, it inhibits epithelial-to-mesenchymal transition (EMT) by attenuating the level of beta-catenin. Therefore, depletion ...


Ste5 Membrane Localization Allows Mapk Pathway Signaling In Trans Between Kinases On Separate Scaffold Molecules, Rachel E. Lamson, Matthew J. Winters, Peter M. Pryciak Jun 2019

Ste5 Membrane Localization Allows Mapk Pathway Signaling In Trans Between Kinases On Separate Scaffold Molecules, Rachel E. Lamson, Matthew J. Winters, Peter M. Pryciak

University of Massachusetts Medical School Faculty Publications

The MAP kinase cascade is a ubiquitous eukaryotic signaling module that can be controlled by a diverse group of scaffold proteins. In budding yeast, activation of the mating MAP kinase cascade involves regulated membrane recruitment of the archetypal scaffold protein Ste5. This event promotes activation of the first kinase, but it also enhances subsequent signal propagation through the remainder of the cascade. By studying this latter effect, we find that membrane recruitment promotes signaling in trans between kinases on separate Ste5 molecules. First, trans signaling requires all Ste5 domains that mediate membrane recruitment, including both protein-binding and membrane-binding domains. Second ...


Mtf1, A Classic Metal Sensing Transcription Factor, Promotes Myogenesis In Response To Copper, Cristina Tavera-Montañez, Sarah J. Hainer, Daniella Cangussu, Shellaina J. V. Gordon, Yao Xiao, Pablo Reyes-Gutierrez, Anthony N. Imbalzano, Juan G. Navea, Thomas G. Fazzio, Teresita Padilla-Benavides Jun 2019

Mtf1, A Classic Metal Sensing Transcription Factor, Promotes Myogenesis In Response To Copper, Cristina Tavera-Montañez, Sarah J. Hainer, Daniella Cangussu, Shellaina J. V. Gordon, Yao Xiao, Pablo Reyes-Gutierrez, Anthony N. Imbalzano, Juan G. Navea, Thomas G. Fazzio, Teresita Padilla-Benavides

University of Massachusetts Medical School Faculty Publications

MTF1 is a conserved metal-binding transcription factor in eukaryotes that binds to conserved DNA sequence motifs, termed metal response elements (MREs). MTF1 responds to metal excess and deprivation, protects cells from oxidative and hypoxic stresses, and is required for embryonic development in vertebrates. We used multiple strategies to identify an unappreciated role for MTF1 and copper (Cu) in cell differentiation. Upon initiation of myogenesis from primary myoblasts, MTF1 expression increased, as did nuclear localization. Mtf1 knockdown impaired differentiation, while addition of non-toxic concentrations of Cu+ enhanced MTF1 expression and promoted myogenesis. Cu+ bound stoichiometrically to a C-terminus tetra-cysteine of MTF1 ...


Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition In Cancer, Monserrat Olea-Flores, Miriam Daniela Zuniga-Eulogio, Miguel Angel Mendoza-Catalan, Hugo Alberto Rodriguez-Ruiz, Eduardo Castaneda-Saucedo, Carlos Ortuno-Pineda, Teresita Padilla-Benavides, Napoleon Navarro-Tito Jun 2019

Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition In Cancer, Monserrat Olea-Flores, Miriam Daniela Zuniga-Eulogio, Miguel Angel Mendoza-Catalan, Hugo Alberto Rodriguez-Ruiz, Eduardo Castaneda-Saucedo, Carlos Ortuno-Pineda, Teresita Padilla-Benavides, Napoleon Navarro-Tito

Open Access Articles

Epithelial-mesenchymal transition (EMT) is a reversible cellular process, characterized by changes in gene expression and activation of proteins, favoring the trans-differentiation of the epithelial phenotype to a mesenchymal phenotype. This process increases cell migration and invasion of tumor cells, progression of the cell cycle, and resistance to apoptosis and chemotherapy, all of which support tumor progression. One of the signaling pathways involved in tumor progression is the MAPK pathway. Within this family, the ERK subfamily of proteins is known for its contributions to EMT. The ERK subfamily is divided into typical (ERK 1/2/5), and atypical (ERK 3/4 ...


Proteome Of The Central Apparatus Of A Ciliary Axoneme, Lei Zhao, Yuqing Hou, Tyler Picariello, Branch Craige, George B. Witman Jun 2019

Proteome Of The Central Apparatus Of A Ciliary Axoneme, Lei Zhao, Yuqing Hou, Tyler Picariello, Branch Craige, George B. Witman

Radiology Publications and Presentations

Nearly all motile cilia have a "9+2" axoneme containing a central apparatus (CA), consisting of two central microtubules with projections, that is essential for motility. To date, only 22 proteins are known to be CA components. To identify new candidate CA proteins, we used mass spectrometry to compare axonemes of wild-type Chlamydomonas and a CA-less mutant. We identified 44 novel candidate CA proteins, of which 13 are conserved in humans. Five of the latter were studied more closely, and all five localized to the CA; therefore, most of the other candidates are likely to also be CA components. Our ...


Adipocyte Acly Facilitates Dietary Carbohydrate Handling To Maintain Metabolic Homeostasis In Females, Sully Fernandez, John M. Viola, Annmarie Torres, Martina Wallace, Sophie Trefely, Steven Zhao, Hayley C. Affronti, Jivani M. Gengatharan, David A. Guertin, Nathaniel W. Snyder, Christian M. Metallo, Kathryn E. Wellen May 2019

Adipocyte Acly Facilitates Dietary Carbohydrate Handling To Maintain Metabolic Homeostasis In Females, Sully Fernandez, John M. Viola, Annmarie Torres, Martina Wallace, Sophie Trefely, Steven Zhao, Hayley C. Affronti, Jivani M. Gengatharan, David A. Guertin, Nathaniel W. Snyder, Christian M. Metallo, Kathryn E. Wellen

Open Access Articles

Sugars and refined carbohydrates are major components of the modern diet. ATP-citrate lyase (ACLY) is upregulated in adipocytes in response to carbohydrate consumption and generates acetyl-coenzyme A (CoA) for both lipid synthesis and acetylation reactions. Here, we investigate the role of ACLY in the metabolic and transcriptional responses to carbohydrates in adipocytes and unexpectedly uncover a sexually dimorphic function in maintaining systemic metabolic homeostasis. When fed a high-sucrose diet, Acly(FAT-/-) females exhibit a lipodystrophy-like phenotype, with minimal fat accumulation, insulin resistance, and hepatic lipid accumulation, whereas Acly(FAT-/-) males have only mild metabolic phenotypes. We find that ACLY is ...


Serum Deprivation Of Mesenchymal Stem Cells Improves Exosome Activity And Alters Lipid And Protein Composition, Reka A. Haraszti, Rachael Miller, Michelle L. Dubuke, Andrew H. Coles, Marie C. Didiot, Dimas Echeverria, Matteo Stoppato, Yves Y. Sere, John D. Leszyk, Julia F. Alterman, Bruno M. D. C. Godinho, Matthew R. Hassler, Rachel Wollacott, Yan Wang, Scott A. Shaffer, Neil Aronin, Anastasia Khvorova May 2019

Serum Deprivation Of Mesenchymal Stem Cells Improves Exosome Activity And Alters Lipid And Protein Composition, Reka A. Haraszti, Rachael Miller, Michelle L. Dubuke, Andrew H. Coles, Marie C. Didiot, Dimas Echeverria, Matteo Stoppato, Yves Y. Sere, John D. Leszyk, Julia F. Alterman, Bruno M. D. C. Godinho, Matthew R. Hassler, Rachel Wollacott, Yan Wang, Scott A. Shaffer, Neil Aronin, Anastasia Khvorova

Open Access Articles

Exosomes can serve as delivery vehicles for advanced therapeutics. The components necessary and sufficient to support exosomal delivery have not been established. Here we connect biochemical composition and activity of exosomes to optimize exosome-mediated delivery of small interfering RNAs (siRNAs). This information is used to create effective artificial exosomes. We show that serum-deprived mesenchymal stem cells produce exosomes up to 22-fold more effective at delivering siRNAs to neurons than exosomes derived from control cells. Proteinase treatment of exosomes stops siRNA transfer, indicating that surface proteins on exosomes are involved in trafficking. Proteomic and lipidomic analyses show that exosomes derived in ...


Arf Gtpases And Their Gefs And Gaps: Concepts And Challenges, Elizabeth Sztul, Pei-Wen Chen, James E. Casanova, Jacqueline Cherfils, Joel B. Dacks, David G. Lambright, Fang-Jen S. Lee, Paul A. Randazzo, Lorraine C. Santy, Annette Schurmann, Ilka Wilhelmi, Marielle E. Yohe, Richard A. Kahn May 2019

Arf Gtpases And Their Gefs And Gaps: Concepts And Challenges, Elizabeth Sztul, Pei-Wen Chen, James E. Casanova, Jacqueline Cherfils, Joel B. Dacks, David G. Lambright, Fang-Jen S. Lee, Paul A. Randazzo, Lorraine C. Santy, Annette Schurmann, Ilka Wilhelmi, Marielle E. Yohe, Richard A. Kahn

Program in Molecular Medicine Publications and Presentations

Detailed structural, biochemical, cell biological, and genetic studies of any gene/protein are required to develop models of its actions in cells. Studying a protein family in the aggregate yields additional information, as one can include analyses of their coevolution, acquisition or loss of functionalities, structural pliability, and the emergence of shared or variations in molecular mechanisms. An even richer understanding of cell biology can be achieved through evaluating functionally linked protein families. In this review, we summarize current knowledge of three protein families: the ARF GTPases, the guanine nucleotide exchange factors (ARF GEFs) that activate them, and the GTPase-activating ...


Targeting Sec61Α By Ipomoeassin F Leads To Highly Cytotoxic Effect, Zhijian Hu May 2019

Targeting Sec61Α By Ipomoeassin F Leads To Highly Cytotoxic Effect, Zhijian Hu

Theses and Dissertations

Ipomoeassin F is a flagship congener of a resin glycoside family that inhibits growth of many tumor cell lines with only single-digital nanomolar IC50 values. However, biological and pharmacological mechanisms of ipomoeassin F have been undefined. To facilitate exploration of the biological and pharmacological properties, we performed sophisticate SAR (Structure–activity relationship) studies of ipomoeassin F to understand its pharmacophore and structure properties so that we can design favorable probes for further biological investigation. By applying appropriate deviates that possess fluorescent groups and similar bio-activity, the target protein was found to be localized in endoplasmic reticulum (ER). Through biotin affinity ...


Sensory Primary Cilium Is A Responsive Camp Microdomain In Renal Epithelia, Rinzhin T. Sherpa, Ashraf M. Mohieldin, Rajasekharreddy Pala, Dagmar Wachten, Rennolds S. Ostrom, Surya M. Nauli Apr 2019

Sensory Primary Cilium Is A Responsive Camp Microdomain In Renal Epithelia, Rinzhin T. Sherpa, Ashraf M. Mohieldin, Rajasekharreddy Pala, Dagmar Wachten, Rennolds S. Ostrom, Surya M. Nauli

Pharmacy Faculty Articles and Research

Primary cilia are hair-like cellular extensions that sense microenvironmental signals surrounding cells. The role of adenylyl cyclases in ciliary function has been of interest because the product of adenylyl cyclase activity, cAMP, is relevant to cilia-related diseases. In the present study, we show that vasopressin receptor type-2 (V2R) is localized to cilia in kidney epithelial cells. Pharmacologic inhibition of V2R with tolvaptan increases ciliary length and mechanosensory function. Genetic knockdown of V2R, however, does not have any effect on ciliary length, although the effect of tolvaptan on ciliary length is dampened. Our study reveals that tolvaptan may have a cilia-specific ...


Amphiphilic Peptides For Efficient Sirna Delivery, Saghar Mozaffari, Emira Bousoik, Farideh Amirrad, Robert Lamboy, Melissa Coyle, Ryley Hall, Abdulaziz Alasmari, Parvin Mahdipoor, Keykavous Parang, Hamidreza Montazeri Aliabadi Apr 2019

Amphiphilic Peptides For Efficient Sirna Delivery, Saghar Mozaffari, Emira Bousoik, Farideh Amirrad, Robert Lamboy, Melissa Coyle, Ryley Hall, Abdulaziz Alasmari, Parvin Mahdipoor, Keykavous Parang, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

A number of amphiphilic cyclic peptides—[FR]4, [WR]5, and [WK]5—containing hydrophobic and positively-charged amino acids were synthesized by Fmoc/tBu solid-phase peptide methods and evaluated for their efficiency in intracellular delivery of siRNA to triple-negative breast cancer cell lines, MDA-MB-231 and MDA-MB-468, in the presence and absence of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE). Among the peptides, [WR]5, which contains alternate tryptophan (W) and arginine (R) residues, was found to be the most efficient in the delivery of siRNA by improving the delivery by more than 3-fold when compared to other synthesized cyclic peptides that were not efficient ...


Single-Cell Rna-Sequencing-Based Crispri Screening Resolves Molecular Drivers Of Early Human Endoderm Development, Ryan M. Genga, Eric M. Kernfeld, Krishna M. Parsi, Teagan J. Parsons, Michael J. Ziller, Rene Maehr Apr 2019

Single-Cell Rna-Sequencing-Based Crispri Screening Resolves Molecular Drivers Of Early Human Endoderm Development, Ryan M. Genga, Eric M. Kernfeld, Krishna M. Parsi, Teagan J. Parsons, Michael J. Ziller, Rene Maehr

Open Access Articles

Studies in vertebrates have outlined conserved molecular control of definitive endoderm (END) development. However, recent work also shows that key molecular aspects of human END regulation differ even from rodents. Differentiation of human embryonic stem cells (ESCs) to END offers a tractable system to study the molecular basis of normal and defective human-specific END development. Here, we interrogated dynamics in chromatin accessibility during differentiation of ESCs to END, predicting DNA-binding proteins that may drive this cell fate transition. We then combined single-cell RNA-seq with parallel CRISPR perturbations to comprehensively define the loss-of-function phenotype of those factors in END development. Following ...


The Erk Mapk Pathway Is Essential For Skeletal Development And Homeostasis, Jung-Min Kim, Yeon-Suk Yang, Kwang Hwan Park, Hwanhee Oh, Matthew B. Greenblatt, Jae-Hyuck Shim Apr 2019

The Erk Mapk Pathway Is Essential For Skeletal Development And Homeostasis, Jung-Min Kim, Yeon-Suk Yang, Kwang Hwan Park, Hwanhee Oh, Matthew B. Greenblatt, Jae-Hyuck Shim

Open Access Articles

Mitogen-activated protein kinases (MAPKs) are a family of protein kinases that function as key signal transducers of a wide spectrum of extracellular stimuli, including growth factors and pro-inflammatory cytokines. Dysregulation of the extracellular signal-regulated kinase (ERK) MAPK pathway is associated with human skeletal abnormalities including Noonan syndrome, neurofibromatosis type 1, and cardiofaciocutaneous syndrome. Here, we demonstrate that ERK activation in osteoprogenitors is required for bone formation during skeletal development and homeostasis. Deletion of Mek1 and Mek2, kinases upstream of ERK MAPK, in osteoprogenitors (Mek1(Osx)Mek2(-/-)), resulted in severe osteopenia and cleidocranial dysplasia (CCD), similar to that seen in humans ...


The Er-Localized Protein Dfcp1 Modulates Er-Lipid Droplet Contact Formation, Dongfang Li, Yan G. Zhao, Di Li, Hongyu Zhao, Jie Huang, Guangyan Miao, Du Feng, Pingsheng Liu, Dong Li, Hong Zhang Apr 2019

The Er-Localized Protein Dfcp1 Modulates Er-Lipid Droplet Contact Formation, Dongfang Li, Yan G. Zhao, Di Li, Hongyu Zhao, Jie Huang, Guangyan Miao, Du Feng, Pingsheng Liu, Dong Li, Hong Zhang

Open Access Articles

Very little is known about the spatiotemporal generation of lipid droplets (LDs) from the endoplasmic reticulum (ER) and the factors that mediate ER-LD contacts for LD growth. Using super-resolution grazing incidence structured illumination microscopy (GI-SIM) live-cell imaging, we reveal that upon LD induction, the ER-localized protein DFCP1 redistributes to nascent puncta on the ER, whose formation depends on triglyceride synthesis. These structures move along the ER and fuse to form expanding LDs. Fusion and expansion of DFCP1-labeled nascent structures is controlled by BSCL2. BSCL2 depletion causes accumulation of nascent DFCP1 structures. DFCP1 overexpression increases LD size and enhances ER-LD contacts ...


Transfer Rna Genes Affect Chromosome Structure And Function Via Local Effects, Omar Hamdani, Tsung-Han S. Hsieh, Oliver J. Rando, Rohinton T. Kamakaka Apr 2019

Transfer Rna Genes Affect Chromosome Structure And Function Via Local Effects, Omar Hamdani, Tsung-Han S. Hsieh, Oliver J. Rando, Rohinton T. Kamakaka

Open Access Articles

The genome is packaged and organized in an ordered, non-random manner and specific chromatin segments contact nuclear substructures to mediate this organization. Transfer RNA genes (tDNAs) are binding sites for transcription factors and architectural proteins and are thought to play an important role in the organization of the genome. In this study, we investigate the role of tDNAs in genomic organization and chromosome function by editing a chromosome so that it lacks any tDNAs. Surprisingly our analyses of this tDNA-less chromosome show that loss of tDNAs does not grossly affect chromatin architecture or chromosome tethering and mobility. However, loss of ...


Vegf/Neuropilin Signaling In Cancer Stem Cells, Arthur M. Mercurio Mar 2019

Vegf/Neuropilin Signaling In Cancer Stem Cells, Arthur M. Mercurio

Arthur M. Mercurio

The function of vascular endothelial growth factor (VEGF) in cancer extends beyond angiogenesis and vascular permeability. Specifically, VEGF-mediated signaling occurs in tumor cells and this signaling contributes to key aspects of tumorigenesis including the self-renewal and survival of cancer stem cells (CSCs). In addition to VEGF receptor tyrosine kinases, the neuropilins (NRPs) are critical for mediating the effects of VEGF on CSCs, primarily because of their ability to impact the function of growth factor receptors and integrins. VEGF/NRP signaling can regulate the expression and function of key molecules that have been implicated in CSC function including Rho family guanosine ...


Inhibition Of Triggering Receptor Expressed On Myeloid Cells 1 Ameliorates Inflammation And Macrophage And Neutrophil Activation In Alcoholic Liver Disease In Mice, David Tornai, Istvan Furi, Zu T. Shen, Alexander B. Sigalov, Sahin Coban, Gyongyi Szabo Mar 2019

Inhibition Of Triggering Receptor Expressed On Myeloid Cells 1 Ameliorates Inflammation And Macrophage And Neutrophil Activation In Alcoholic Liver Disease In Mice, David Tornai, Istvan Furi, Zu T. Shen, Alexander B. Sigalov, Sahin Coban, Gyongyi Szabo

Gyongyi Szabo

Alcoholic liver disease (ALD) is characterized by macrophage and neutrophil leukocyte recruitment and activation in the liver. Damage- and pathogen-associated molecular patterns contribute to a self-perpetuating proinflammatory state in ALD. Triggering receptor expressed on myeloid cells 1 (TREM-1) is a surface receptor that amplifies inflammation induced by toll-like receptors (TLRs) and is expressed on neutrophils and monocytes/macrophages. We hypothesized that TREM-1 signaling contributes to proinflammatory pathway activation in ALD. Using an in vivo ALD model in mice, we tested the effects of ligand-independent TREM-1 inhibitory peptides that were formulated into human high-density lipoprotein (HDL)-mimicking complexes GF9-HDL and GA ...


Adenosine Triphosphate Is Co-Secreted With Glucagon-Like Peptide-1 To Modulate Intestinal Enterocytes And Afferent Neurons, Van B. Lu, Juraj Rievaj, Elisabeth A. O'Flaherty, Christopher A. Smith, Ramona Pais, Luke A. Pattison, Gwen Tolhurst, Andrew B. Leiter, David C. Bulmer, Fiona M. Gribble, Frank Reimann Mar 2019

Adenosine Triphosphate Is Co-Secreted With Glucagon-Like Peptide-1 To Modulate Intestinal Enterocytes And Afferent Neurons, Van B. Lu, Juraj Rievaj, Elisabeth A. O'Flaherty, Christopher A. Smith, Ramona Pais, Luke A. Pattison, Gwen Tolhurst, Andrew B. Leiter, David C. Bulmer, Fiona M. Gribble, Frank Reimann

Open Access Articles

Enteroendocrine cells are specialised sensory cells located in the intestinal epithelium and generate signals in response to food ingestion. Whilst traditionally considered hormone-producing cells, there is evidence that they also initiate activity in the afferent vagus nerve and thereby signal directly to the brainstem. We investigate whether enteroendocrine L-cells, well known for their production of the incretin hormone glucagon-like peptide-1 (GLP-1), also release other neuro-transmitters/modulators. We demonstrate regulated ATP release by ATP measurements in cell supernatants and by using sniffer patches that generate electrical currents upon ATP exposure. Employing purinergic receptor antagonists, we demonstrate that evoked ATP release from ...


Receptor Interacting Protein Kinase 3 (Rip3) Regulates Ipscs Generation Through Modulating Cell Cycle Progression Genes, Ahmad Al-Moujahed, Bo Tian, Nikolaos E. Efstathiou, Eleni K. Konstantinou, Mien Hoang, Haijiang Lin, Joan W. Miller, Demetrios G. Vavvas Mar 2019

Receptor Interacting Protein Kinase 3 (Rip3) Regulates Ipscs Generation Through Modulating Cell Cycle Progression Genes, Ahmad Al-Moujahed, Bo Tian, Nikolaos E. Efstathiou, Eleni K. Konstantinou, Mien Hoang, Haijiang Lin, Joan W. Miller, Demetrios G. Vavvas

Open Access Articles

The molecular mechanisms involved in induced pluripotent stem cells (iPSCs) generation are poorly understood. The cell death machinery of apoptosis-inducing caspases have been shown to facilitate the process of iPSCs reprogramming. However, the effect of other cell death processes, such as programmed necrosis (necroptosis), on iPSCs induction has not been studied. In this study, we investigated the role of receptor-interacting protein kinase 3 (RIP3), an essential regulator of necroptosis, in reprogramming mouse embryonic fibroblast cells (MEFs) into iPSCs. RIP3 was found to be upregulated in iPSCs compared to MEFs. Deletion of RIP3 dramatically suppressed the reprogramming of iPSCs (~82%). RNA-seq ...