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Molecular Biology

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2011

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Articles 1 - 30 of 82

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Spt5 Affects The Rate Of Mrna Degradation And Physically Interacts With Ccr4 But Does Not Control Mrna Deadenylation, Yajun Cui, Yueh-Chin Chiang, Palaniswamy Viswanathan, Darren J. Lee, Clyde L. Denis Dec 2011

Spt5 Affects The Rate Of Mrna Degradation And Physically Interacts With Ccr4 But Does Not Control Mrna Deadenylation, Yajun Cui, Yueh-Chin Chiang, Palaniswamy Viswanathan, Darren J. Lee, Clyde L. Denis

New Hampshire Agricultural Experiment Station

The CCR4-NOT complex has been shown to have multiple roles in mRNA metabolism, including that of transcriptional elongation, mRNA transport, and nuclear exosome function, but the primary function of CCR4 and CAF1 is in the deadenylation and degradation of cytoplasmic mRNA. As previous genetic analysis supported an interaction between SPT5, known to be involved in transcriptional elongation, and that of CCR4, the physical association of SPT5 with CCR4 was examined. A two-hybrid screen utilizing the deadenylase domain of CCR4 as a bait identified SPT5 as a potential interacting protein. SPT5 at its physiological concentration was shown to immunoprecipitate CCR4 and ...


Son Maintains Accurate Splicing For A Subset Of Human Pre-Mrnas, Alok Sharma, Michael P. Markey, Keshia Torres-Munoz, Sapna Varia, Madhavi P. Kadakia, Athanasios Bubulya, Paula A. Bubulya Dec 2011

Son Maintains Accurate Splicing For A Subset Of Human Pre-Mrnas, Alok Sharma, Michael P. Markey, Keshia Torres-Munoz, Sapna Varia, Madhavi P. Kadakia, Athanasios Bubulya, Paula A. Bubulya

Biochemistry and Molecular Biology Faculty Publications

Serine-arginine-rich (SR) proteins play a key role in alternative pre-mRNA splicing in eukaryotes. We recently showed that a large SR protein called Son has unique repeat motifs that are essential for maintaining the subnuclear organization of pre-mRNA processing factors in nuclear speckles. Motif analysis of Son highlights putative RNA interaction domains that suggest a direct role for Son in pre-mRNA splicing. Here, we used in situ approaches to show that Son localizes to a reporter minigene transcription site, and that RNAi-mediated Son depletion causes exon skipping on reporter transcripts at this transcription site. A genome-wide exon microarray analysis was performed ...


The Loss Of C-Jun N-Terminal Protein Kinase Activity Prevents The Amyloidogenic Cleavage Of Amyloid Precursor Protein And The Formation Of Amyloid Plaques In Vivo, Sonia Mazzitelli, Ping Xu, Isidre Ferrer, Roger J. Davis, Cathy Tournier Nov 2011

The Loss Of C-Jun N-Terminal Protein Kinase Activity Prevents The Amyloidogenic Cleavage Of Amyloid Precursor Protein And The Formation Of Amyloid Plaques In Vivo, Sonia Mazzitelli, Ping Xu, Isidre Ferrer, Roger J. Davis, Cathy Tournier

Davis Lab Publications

Phosphorylation plays a central role in the dynamic regulation of the processing of the amyloid precursor protein (APP) and the production of amyloid-beta (Abeta), one of the clinically most important factors that determine the onset of Alzheimer's disease (AD). This has led to the hypothesis that aberrant Abeta production associated with AD results from regulatory defects in signal transduction. However, conflicting findings have raised a debate over the identity of the signaling pathway that controls APP metabolism. Here, we demonstrate that activation of the c-Jun N-terminal protein kinase (JNK) is essential for mediating the apoptotic response of neurons to ...


Differential Il-21 Signaling In Apcs Leads To Disparate Th17 Differentiation In Diabetes-Susceptible Nod And Diabetes-Resistant Nod.Idd3 Mice., Sue M. Liu, David H. Lee, Jenna M. Sullivan, Denise Chung, Anneli Jäger, Bennett O V. Shum, Nora E. Sarvetnick, Ana C. Anderson, Vijay K. Kuchroo Nov 2011

Differential Il-21 Signaling In Apcs Leads To Disparate Th17 Differentiation In Diabetes-Susceptible Nod And Diabetes-Resistant Nod.Idd3 Mice., Sue M. Liu, David H. Lee, Jenna M. Sullivan, Denise Chung, Anneli Jäger, Bennett O V. Shum, Nora E. Sarvetnick, Ana C. Anderson, Vijay K. Kuchroo

Journal Articles: Regenerative Medicine

Type 1 diabetes (T1D) is an autoimmune disease that shows familial aggregation in humans and likely has genetic determinants. Disease linkage studies have revealed many susceptibility loci for T1D in mice and humans. The mouse T1D susceptibility locus insulin-dependent diabetes susceptibility 3 (Idd3), which has a homologous genetic interval in humans, encodes cytokine genes Il2 and Il21 and regulates diabetes and other autoimmune diseases; however, the cellular and molecular mechanisms of this regulation are still being elucidated. Here we show that T cells from NOD mice produce more Il21 and less Il2 and exhibit enhanced Th17 cell generation compared with ...


Mlk3 Regulates Bone Development Downstream Of The Faciogenital Dysplasia Protein Fgd1 In Mice, Weiguo Zou, Matthew B. Greenblatt, Jae-Hyuck Shim, Shashi Kant, Bo Zhai, Sutada Lotinun, Nicholas Brady, Dorothy Zhang Hu, Steven P. Gygi, Roland Baron, Roger J. Davis, Dallas Jones, Laurie H. Glimcher Nov 2011

Mlk3 Regulates Bone Development Downstream Of The Faciogenital Dysplasia Protein Fgd1 In Mice, Weiguo Zou, Matthew B. Greenblatt, Jae-Hyuck Shim, Shashi Kant, Bo Zhai, Sutada Lotinun, Nicholas Brady, Dorothy Zhang Hu, Steven P. Gygi, Roland Baron, Roger J. Davis, Dallas Jones, Laurie H. Glimcher

Davis Lab Publications

Mutations in human FYVE, RhoGEF, and PH domain-containing 1 (FGD1) cause faciogenital dysplasia (FGDY; also known as Aarskog syndrome), an X-linked disorder that affects multiple skeletal structures. FGD1 encodes a guanine nucleotide exchange factor (GEF) that specifically activates the Rho GTPase CDC42. However, the mechanisms by which mutations in FGD1 affect skeletal development are unknown. Here, we describe what we believe to be a novel signaling pathway in osteoblasts initiated by FGD1 that involves the MAP3K mixed-lineage kinase 3 (MLK3). We observed that MLK3 functions downstream of FGD1 to regulate ERK and p38 MAPK, which in turn phosphorylate and activate ...


Electrosensory Ampullary Organs Are Derived From Lateral Line Placodes In Bony Fishes, Melissa S. Modrell, William E. Benis, R. Glenn Northcutt, Marcus C. Davis, Clare V.H. Baker Oct 2011

Electrosensory Ampullary Organs Are Derived From Lateral Line Placodes In Bony Fishes, Melissa S. Modrell, William E. Benis, R. Glenn Northcutt, Marcus C. Davis, Clare V.H. Baker

Faculty Publications

Electroreception is an ancient subdivision of the lateral line sensory system, found in all major vertebrate groups (though lost in frogs, amniotes and most ray-finned fishes). Electroreception is mediated by 'hair cells' in ampullary organs, distributed in fields flanking lines of mechanosensory hair cell-containing neuromasts that detect local water movement. Neuromasts, and afferent neurons for both neuromasts and ampullary organs, develop from lateral line placodes. Although ampullary organs in the axolotl (a representative of the lobe-finned clade of bony fishes) are lateral line placode-derived, non-placodal origins have been proposed for electroreceptors in other taxa. Here we show morphological and molecular ...


Splice Variant–Specific Cellular Function Of The Formin Inf2 In Maintenance Of Golgi Architecture, Vinay Ramabhadran, Farida Korobova, Gilbert J. Rahme, Henry N. Higgs Oct 2011

Splice Variant–Specific Cellular Function Of The Formin Inf2 In Maintenance Of Golgi Architecture, Vinay Ramabhadran, Farida Korobova, Gilbert J. Rahme, Henry N. Higgs

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

INF2 is a unique formin that can both polymerize and depolymerize actin filaments. Mutations in INF2 cause the kidney disease focal and segmental glomerulosclerosis. INF2 can be expressed as two C-terminal splice variants: CAAX and non-CAAX. The CAAX isoform contains a C-terminal prenyl group and is tightly bound to endoplasmic reticulum (ER). The localization pattern and cellular function of the non-CAAX isoform have not been studied. Here we find that the two isoforms are expressed in a cell type-dependent manner, with CAAX predominant in 3T3 fibroblasts and non-CAAX predominant in U2OS, HeLa, and Jurkat cells. Although INF2-CAAX is ER localized ...


A Brain-Derived Mecp2 Complex Supports A Role For Mecp2 In Rna Processing, Steven W. Long, Jenny Y. Y. Ooi, Peter M. Yau, Peter L. Jones Oct 2011

A Brain-Derived Mecp2 Complex Supports A Role For Mecp2 In Rna Processing, Steven W. Long, Jenny Y. Y. Ooi, Peter M. Yau, Peter L. Jones

Peter Jones Lab Publications

Mutations in MECP2 (methyl-CpG-binding protein 2) are linked to the severe postnatal neurodevelopmental disorder RTT (Rett syndrome). MeCP2 was originally characterized as a transcriptional repressor that preferentially bound methylated DNA; however, recent results indicate MeCP2 is a multifunctional protein. MeCP2 binding is now associated with certain expressed genes and involved in nuclear organization as well, indicating that its gene regulatory function is context-dependent. In addition, MeCP2 is proposed to regulate mRNA splicing and a mouse model for RTT shows aberrant mRNA splicing. To further understand MeCP2 and potential roles in RTT pathogenesis, we have employed a biochemical approach to identify ...


Dopamine Regulation Of Cone-Cone Gap Junctions In Ground Squirrel Retina, Xiaoyu Li '12, Steven Devries Oct 2011

Dopamine Regulation Of Cone-Cone Gap Junctions In Ground Squirrel Retina, Xiaoyu Li '12, Steven Devries

Student Publications & Research

Cone photoreceptors are electrically coupled such that when the electrical potential in one cell changes, it also changes in adjacent, coupled cells. Phosphorylation of the cone gap junction protein, connexin 36 (Cx36), determines whether a coupling channel is “open” or “closed”. Cx36- containing gap junctions are phosphorylated in the open state and dephosphorylated in the closed state. Cone-cone gap junction modulation has not been extensively studied, however, the presence of rod-cone gap junction modulation raises the possibility that the same is true for cone pairs. Pieces of thirteen-lined ground squirrel retina were removed from the eye and the tissue was ...


Tnf-Stimulated Map Kinase Activation Mediated By A Rho Family Gtpase Signaling Pathway, Shashi Kant, Wojciech Swat, Sheng Zhang, Zhong-Yin Zhang, Benjamin G. Neel, Richard A. Flavell, Roger J. Davis Oct 2011

Tnf-Stimulated Map Kinase Activation Mediated By A Rho Family Gtpase Signaling Pathway, Shashi Kant, Wojciech Swat, Sheng Zhang, Zhong-Yin Zhang, Benjamin G. Neel, Richard A. Flavell, Roger J. Davis

Davis Lab Publications

The biological response to tumor necrosis factor (TNF) involves activation of MAP kinases. Here we report a mechanism of MAP kinase activation by TNF that is mediated by the Rho GTPase family members Rac/Cdc42. This signaling pathway requires Src-dependent activation of the guanosine nucleotide exchange factor Vav, activation of Rac/Cdc42, and the engagement of the Rac/Cdc42 interaction site (CRIB motif) on mixed-lineage protein kinases (MLKs). We show that this pathway is essential for full MAP kinase activation during the response to TNF. Moreover, this MLK pathway contributes to inflammation in vivo.


The Pcdp1 Complex Coordinates The Activity Of Dynein Isoforms To Produce Wild-Type Ciliary Motility, Christen G. Dipetrillo, Elizabeth F. Smith Sep 2011

The Pcdp1 Complex Coordinates The Activity Of Dynein Isoforms To Produce Wild-Type Ciliary Motility, Christen G. Dipetrillo, Elizabeth F. Smith

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

Generating the complex waveforms characteristic of beating cilia requires the coordinated activity of multiple dynein isoforms anchored to the axoneme. We previously identified a complex associated with the C1d projection of the central apparatus that includes primary ciliary dyskinesia protein 1 (Pcdp1). Reduced expression of complex members results in severe motility defects, indicating that C1d is essential for wild-type ciliary beating. To define a mechanism for Pcdp1/C1d regulation of motility, we took a functional and structural approach combined with mutants lacking C1d and distinct subsets of dynein arms. Unlike mutants completely lacking the central apparatus, dynein-driven microtubule sliding velocities ...


Differential Interactions Of The Formins Inf2, Mdia1, And Mdia2 With Microtubules, Jeremie Gaillard, Bvinay Ramabhadran, Emmanuelle Neumanne, Pinar Gurel, Laurent Blanchoin, Marylin Vantard, Henry N. Higgs Sep 2011

Differential Interactions Of The Formins Inf2, Mdia1, And Mdia2 With Microtubules, Jeremie Gaillard, Bvinay Ramabhadran, Emmanuelle Neumanne, Pinar Gurel, Laurent Blanchoin, Marylin Vantard, Henry N. Higgs

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

A number of cellular processes use both microtubules and actin filaments, but the molecular machinery linking these two cytoskeletal elements remains to be elucidated in detail. Formins are actin-binding proteins that have multiple effects on actin dynamics, and one formin, mDia2, has been shown to bind and stabilize microtubules through its formin homology 2 (FH2) domain. Here we show that three formins, INF2, mDia1, and mDia2, display important differences in their interactions with microtubules and actin. Constructs containing FH1, FH2, and C-terminal domains of all three formins bind microtubules with high affinity (K(d) < 100 nM). However, only mDia2 binds microtubules at 1:1 stoichiometry, with INF2 and mDia1 showing saturating binding at approximately 1:3 (formin dimer:tubulin dimer). INF2-FH1FH2C is a potent microtubule-bundling protein, an effect that results in a large reduction in catastrophe rate. In contrast, neither mDia1 nor mDia2 is a potent microtubule bundler. The C-termini of mDia2 and INF2 have different functions in microtubule interaction, with mDia2's C-terminus required for high-affinity binding and INF2's C-terminus required for bundling. mDia2's C-terminus directly binds microtubules with submicromolar affinity. These formins also differ in their abilities to bind actin and microtubules simultaneously. Microtubules strongly inhibit actin polymerization by mDia2, whereas they moderately inhibit mDia1 and have no effect on INF2. Conversely, actin monomers inhibit microtubule binding/bundling by INF2 but do not affect mDia1 or mDia2. These differences in interactions with microtubules and actin suggest differential function in cellular processes requiring both cytoskeletal elements.


A Novel Labda-7,13e-Dien-15-Ol-Producing Bifunctional Diterpene Synthase From Selaginella Moellendorffii, Sibongile Mafu, Matthew L. Hillwig, Reuben J. Peters Sep 2011

A Novel Labda-7,13e-Dien-15-Ol-Producing Bifunctional Diterpene Synthase From Selaginella Moellendorffii, Sibongile Mafu, Matthew L. Hillwig, Reuben J. Peters

Biochemistry, Biophysics and Molecular Biology Publications

Vascular plants invariably contain a class II diterpene cyclase (EC 5.5.1.x), as an ent-copalyl diphosphate synthase is required for gibberellin phytohormone biosynthesis. This has provided the basis for evolution of a functionally diverse enzymatic family.[1] These biocatalysts fold their substrate, the general diterpenoid precursor (E,E,E)-geranylgeranyl diphosphate (GGPP), to bring the terminal three carbon-carbon double bonds into proximity with each other, and then carry out bicyclization via a protonation-initiated carbocation cascade reaction. The resulting labda-15-en-8-yl+ diphosphate intermediate is most commonly quenched by deprotonation at an exocyclic methyl, as in the production of labdadienyl/copalyl ...


Drosophila Iap1-Mediated Ubiquitylation Controls Activation Of The Initiator Caspase Dronc Independent Of Protein Degradation, Tom V. Lee, Yun Fan, Shiuan Wang, Mayank Srivastava, Meike Broemer, Pascal Meier, Andreas Bergmann Sep 2011

Drosophila Iap1-Mediated Ubiquitylation Controls Activation Of The Initiator Caspase Dronc Independent Of Protein Degradation, Tom V. Lee, Yun Fan, Shiuan Wang, Mayank Srivastava, Meike Broemer, Pascal Meier, Andreas Bergmann

Molecular, Cell and Cancer Biology Publications

Ubiquitylation targets proteins for proteasome-mediated degradation and plays important roles in many biological processes including apoptosis. However, non-proteolytic functions of ubiquitylation are also known. In Drosophila, the inhibitor of apoptosis protein 1 (DIAP1) is known to ubiquitylate the initiator caspase DRONC in vitro. Because DRONC protein accumulates in diap1 mutant cells that are kept alive by caspase inhibition ("undead" cells), it is thought that DIAP1-mediated ubiquitylation causes proteasomal degradation of DRONC, protecting cells from apoptosis. However, contrary to this model, we show here that DIAP1-mediated ubiquitylation does not trigger proteasomal degradation of full-length DRONC, but serves a non-proteolytic function. Our ...


The Filament-Forming Protein Pil1 Assembles Linear Eisosomes In Fission Yeast, Ruth Kabeche, Suzanne Baldissard, John Hammond, Louisa Howard, James B. Moseley Aug 2011

The Filament-Forming Protein Pil1 Assembles Linear Eisosomes In Fission Yeast, Ruth Kabeche, Suzanne Baldissard, John Hammond, Louisa Howard, James B. Moseley

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

The cortical cytoskeleton mediates a range of cellular activities such as endocytosis, cell motility, and the maintenance of cell rigidity. Traditional polymers, including actin, microtubules, and septins, contribute to the cortical cytoskeleton, but additional filament systems may also exist. In yeast cells, cortical structures called eisosomes generate specialized domains termed MCCs to cluster specific proteins at sites of membrane invaginations. Here we show that the core eisosome protein Pil1 forms linear cortical filaments in fission yeast cells and that purified Pil1 assembles into filaments in vitro. In cells, Pil1 cortical filaments are excluded from regions of cell growth and are ...


Serum- And Glucocorticoid-Induced Kinase 3 In Recycling Endosomes Mediates Acute Activation Of Na+/H+ Exchanger Nhe3 By Glucocorticoids, Peijian He, Sei-Jung Lee, Songbai Lin, Ursula Seidler, Florian Lang, Geza Fejes-Toth, Aniko Naray-Fejes-Toth, C. Chris Yun Aug 2011

Serum- And Glucocorticoid-Induced Kinase 3 In Recycling Endosomes Mediates Acute Activation Of Na+/H+ Exchanger Nhe3 By Glucocorticoids, Peijian He, Sei-Jung Lee, Songbai Lin, Ursula Seidler, Florian Lang, Geza Fejes-Toth, Aniko Naray-Fejes-Toth, C. Chris Yun

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

Na(+)/H(+) exchanger 3 (NHE3) is the major Na(+) transporter in the intestine. Serum- and glucocorticoid-induced kinase (SGK) 1 interacts with NHE regulatory factor 2 (NHERF2) and mediates activation of NHE3 by dexamethasone (Dex) in cultured epithelial cells. In this study, we compared short-term regulation of NHE3 by Dex in SGK1-null and NHERF2-null mice. In comparison to wild-type mice, loss of SGK1 or NHERF2 significantly attenuated regulation of NHE3 by Dex but did not completely obliterate the effect. We show that transfection of SGK2 or SGK3 in PS120 cells resulted in robust activation of NHE3 by Dex. However, unlike SGK1 ...


Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley Aug 2011

Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley

STAR (STEM Teacher and Researcher) Presentations

Salmonids, such as Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss), are a staple economic, recreational, tribal, and environmental resource, yet many populations are unsustainable. This study was part of a broad scale effort to monitor the impact of downstream migration obstacles on juvenile salmonid health and survival, which is an essential step towards increasing Smolt-to-Adult Return ratios (SARs). The objective of this study was to determine if juvenile Chinook salmon and steelhead exhibit differing quantities of alphaII-Spectrin Breakdown Products (SBDPs) over two consecutive spring migration periods, indicative of neurogenesis rate and/or biological response to head injury. AlphaII-Spectrin is ...


Computational Identification Of Protein Catalytic Sites: Tests, Validation, Dan Kirshner, Jerome Nilmeier, Felice Lightstone Aug 2011

Computational Identification Of Protein Catalytic Sites: Tests, Validation, Dan Kirshner, Jerome Nilmeier, Felice Lightstone

STAR (STEM Teacher and Researcher) Presentations

This project is one element of the analysis “pipeline” to characterize an organism that previously has not been well-studied. Once a protein of unknown structure has been computationally modeled (based on its sequence similarity to proteins with solved structures), then catalytic sites are identified on the model by comparison to a library of known sites. This work tested the identification algorithms with a set of proteins that have known structures and catalytic sites.


Temporal Uncoupling Of The Dna Methylome And Transcriptional Repression During Embryogenesis, Ozren Bogdanovic, Steven W. Long, Simon J. Van Heeringen, Arie B. Brinkman, Jose Luis Gomez-Skarmeta, Hendrik G. Stunnenberg, Peter L. Jones, Gert Jan C. Veenstra Aug 2011

Temporal Uncoupling Of The Dna Methylome And Transcriptional Repression During Embryogenesis, Ozren Bogdanovic, Steven W. Long, Simon J. Van Heeringen, Arie B. Brinkman, Jose Luis Gomez-Skarmeta, Hendrik G. Stunnenberg, Peter L. Jones, Gert Jan C. Veenstra

Peter Jones Lab Publications

DNA methylation is a tightly regulated epigenetic mark associated with transcriptional repression. Next-generation sequencing of purified methylated DNA obtained from early Xenopus tropicalis embryos demonstrates that this genome is heavily methylated during blastula and gastrula stages. Although DNA methylation is largely absent from transcriptional start sites marked with histone H3 lysine 4 trimethylation (H3K4me3), we find both promoters and gene bodies of active genes robustly methylated. In contrast, DNA methylation is absent in large H3K27me3 domains, indicating that these two repression pathways have different roles. Comparison with chromatin state maps of human ES cells reveals strong conservation of epigenetic makeup ...


Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe Aug 2011

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

Theses, Dissertations, and Student Research in Agronomy and Horticulture

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an NADPH ...


Characterization Of Rnai-Defective Mutants -- Mut13-2 And Mut20 -- In Chlamydomonas Reinhardtii, Arit Ghosh Jul 2011

Characterization Of Rnai-Defective Mutants -- Mut13-2 And Mut20 -- In Chlamydomonas Reinhardtii, Arit Ghosh

Dissertations and Theses in Biological Sciences

RNA interference (RNAi) is a highly conserved and sequence-specific process for regulation of gene expression. At the heart of the RNAi machinery lie 21-24 nt small non-coding RNA molecules which are able to downregulate the expression of cognate sequences, by causing degradation or translational repression of mRNAs. These noncoding RNAs act via the effector RNA-induced silencing complex (RISC), which includes core proteins such as the Argonautes (AGOs). Two Chlamydomonas reinhardtii RNAi-defective mutants, Mut13-2 and Mut20, show deletions of various domains of the Tudor Staphylococcal Nuclease 1 (TSN1) gene. TSN1 has already been recognized as a component of the RNA-induced silencing ...


Sunday Driver/Jip3 Binds Kinesin Heavy Chain Directly And Enhances Its Motility, Faneng Sun, Chuanmei Zhu, Ram Dixit, Valeria Cavalli Jul 2011

Sunday Driver/Jip3 Binds Kinesin Heavy Chain Directly And Enhances Its Motility, Faneng Sun, Chuanmei Zhu, Ram Dixit, Valeria Cavalli

Biology Faculty Publications & Presentations

Neuronal development, function and repair critically depend on axonal transport of vesicles and protein complexes, which is mediated in part by the molecular motor kinesin‐1. Adaptor proteins recruit kinesin‐1 to vesicles via direct association with kinesin heavy chain (KHC), the force‐generating component, or via the accessory light chain (KLC). Binding of adaptors to the motor is believed to engage the motor for microtubule‐based transport. We report that the adaptor protein Sunday Driver (syd, also known as JIP3 or JSAP1) interacts directly with KHC, in addition to and independently of its known interaction with KLC. Using an ...


An Interaction Between The Walker A And D-Loop Motifs Is Critical To Atp Hydrolysis And Cooperativity In Bacteriophage T4 Rad50, Metzere Bierlein De La Rosa, Scott W. Nelson Jul 2011

An Interaction Between The Walker A And D-Loop Motifs Is Critical To Atp Hydrolysis And Cooperativity In Bacteriophage T4 Rad50, Metzere Bierlein De La Rosa, Scott W. Nelson

Biochemistry, Biophysics and Molecular Biology Publications

The ATP binding cassette (ABC) proteins make up a large superfamily with members coming from all kingdoms. The functional form of the ABC protein nucleotide binding domain (NBD) is dimeric with ATP binding sites shared between subunits. The NBD is defined by six motifs: the Walker A, Q-loop, Signature, Walker-B, D-loop, and H-loop. The D-loop contains a conserved aspartate whose function is not clear but has been proposed to be involved in cross-talk between ATP binding sites. Structures of various ABC proteins suggest an interaction between the D-loop aspartate and an asparagine residue located in Walker A loop of the ...


Free Energies For Coarse-Grained Proteins By Integrating Multibody Statistical Contact Potentials With Entropies From Elastic Network Models, Michael T. Zimmermann, Sumudu P. Leelananda, Pawel Gniewek, Yaping Feng, Robert L. Jernigan, Andrzej Kloczkowski Jul 2011

Free Energies For Coarse-Grained Proteins By Integrating Multibody Statistical Contact Potentials With Entropies From Elastic Network Models, Michael T. Zimmermann, Sumudu P. Leelananda, Pawel Gniewek, Yaping Feng, Robert L. Jernigan, Andrzej Kloczkowski

Biochemistry, Biophysics and Molecular Biology Publications

We propose a novel method of calculation of free energy for coarse grained models of proteins by combining our newly developed multibody potentials with entropies computed from elastic network models of proteins. Multi-body potentials have been of much interest recently because they take into account three dimensional interactions related to residue packing and capture the cooperativity of these interactions in protein structures. Combining four-body non-sequential, four-body sequential and pairwise short range potentials with optimized weights for each term, our coarse-grained potential improved recognition of native structure among misfolded decoys, outperforming all other contact potentials for CASP8 decoy sets and performance ...


What Is New For An Old Molecule? Systematic Review And Recommendations On The Use Of Resveratrol, Ole Vang, Nihal Ahmad, Karen Brown, Anna Csiszar, Thomas Szekeres, Thomas Walle, Joseph M. Wu Jun 2011

What Is New For An Old Molecule? Systematic Review And Recommendations On The Use Of Resveratrol, Ole Vang, Nihal Ahmad, Karen Brown, Anna Csiszar, Thomas Szekeres, Thomas Walle, Joseph M. Wu

NYMC Faculty Publications

BACKGROUND: Resveratrol is a natural compound suggested to have beneficial health effects. However, people are consuming resveratrol for this reason without having the adequate scientific evidence for its effects in humans. Therefore, scientific valid recommendations concerning the human intake of resveratrol based on available published scientific data are necessary. Such recommendations were formulated after the Resveratrol 2010 conference, held in September 2010 in Helsingør, Denmark.

METHODOLOGY: Literature search in databases as PUBMED and ISI Web of Science in combination with manual search was used to answer the following five questions: (1)Can resveratrol be recommended in the prevention or treatment ...


Transplantation Of Bdnf-Secreting Mesenchymal Stem Cells Provides Neuroprotection In Chronically Hypertensive Rat Eyes, Matthew M. Harper, Sinisa D. Grozdanic, Bas Blits, Markus H. Kuehn, Daniel Zamzow, Janice E. Buss, Randy H. Kardon, Donald S. Sakaguchi Jun 2011

Transplantation Of Bdnf-Secreting Mesenchymal Stem Cells Provides Neuroprotection In Chronically Hypertensive Rat Eyes, Matthew M. Harper, Sinisa D. Grozdanic, Bas Blits, Markus H. Kuehn, Daniel Zamzow, Janice E. Buss, Randy H. Kardon, Donald S. Sakaguchi

Genetics, Development and Cell Biology Publications

Purpose.: To evaluate the ability of mesenchymal stem cells (MSCs) engineered to produce and secrete brain-derived neurotrophic factor (BDNF) to protect retinal function and structure after intravitreal transplantation in a rat model of chronic ocular hypertension (COH).

Methods.: COH was induced by laser cauterization of trabecular meshwork and episcleral veins in rat eyes. COH eyes received an intravitreal transplant of MSCs engineered to express BDNF and green fluorescent protein (BDNF-MSCs) or just GFP (GFP-MSCs). Computerized pupillometry and electroretinography (ERG) were performed to assess optic nerve and retinal function. Quantification of optic nerve damage was performed by counting retinal ganglion cells ...


Functional Evaluation Of Bacteriophage T4 Rad50 Signature Motif Residues, Timothy J. Herdendorf, Scott W. Nelson Jun 2011

Functional Evaluation Of Bacteriophage T4 Rad50 Signature Motif Residues, Timothy J. Herdendorf, Scott W. Nelson

Biochemistry, Biophysics and Molecular Biology Publications

The repair of DNA double-strand breaks (DSBs) is essential to maintaining the integrity of the genome, and organisms have evolved a conserved mechanism to facilitate their repair. In eukaryotes, archaea, and some bacteriophage, a complex made up of Mre11 and Rad50 (MR complex), which are a nuclease and ATPase, respectively, is involved in the initial processing of DSBs. Rad50 is a member of the ATP Binding Cassette (ABC) protein superfamily, the members of which contain an important Signature motif that acts in trans to complete the dimeric ATP binding site. To explore the functional relevance of this motif, four of ...


Multibody Coarse-Grained Potentials For Native Structure Recognition And Quality Assessment Of Protein Models, Pawel Gniewek, Sumudu P. Leelananda, Andrzej Kolinski, Robert L. Jernigan, Andrzej Kloczkowski Jun 2011

Multibody Coarse-Grained Potentials For Native Structure Recognition And Quality Assessment Of Protein Models, Pawel Gniewek, Sumudu P. Leelananda, Andrzej Kolinski, Robert L. Jernigan, Andrzej Kloczkowski

Biochemistry, Biophysics and Molecular Biology Publications

Multi-body potentials have been of much interest recently because they take into account three dimensional interactions related to residue packing and capture the cooperativity of these interactions in protein structures. Our goal was to combine long range multi-body potentials and short range potentials to improve recognition of native structure among misfolded decoys. We optimized the weights for four-body non-sequential, four-body sequential and short range potentials in order to obtain optimal model ranking results for threading and have compared these data against results obtained with other potentials. (Twenty six different coarse-grained potentials from the Potentials ‘R’Us web server have been ...


Deficiency Of Maize Starch-Branching Enzyme I Results In Altered Starch Fine Structure, Decreased Digestibility And Reduced Coleoptile Growth During Germination, Huan Xia, Marna Yandeau-Nelson, Donald B. Thompson, Mark J. Guiltinan May 2011

Deficiency Of Maize Starch-Branching Enzyme I Results In Altered Starch Fine Structure, Decreased Digestibility And Reduced Coleoptile Growth During Germination, Huan Xia, Marna Yandeau-Nelson, Donald B. Thompson, Mark J. Guiltinan

Biochemistry, Biophysics and Molecular Biology Publications

Background: Two distinct starch branching enzyme (SBE) isoforms predate the divergence of monocots and dicots and have been conserved in plants since then. This strongly suggests that both SBEI and SBEII provide unique selective advantages to plants. However, no phenotype for the SBEI mutation, sbe1a, had been previously observed. To explore this incongruity the objective of the present work was to characterize functional and molecular phenotypes of both sbe1a and wild-type (Wt) in the W64A maize inbred line.

Results: Endosperm starch granules from the sbe1a mutant were more resistant to digestion by pancreatic aamylase, and the sbe1a mutant starch had ...


The Csc Is Required For Complete Radial Spoke Assembly And Wild-Type Ciliary Motility, Erin E. Dymek, Thomas Heuser, Daniela Nicastro, Elizabeth F. Smith May 2011

The Csc Is Required For Complete Radial Spoke Assembly And Wild-Type Ciliary Motility, Erin E. Dymek, Thomas Heuser, Daniela Nicastro, Elizabeth F. Smith

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

The ubiquitous calcium binding protein, calmodulin (CaM), plays a major role in regulating the motility of all eukaryotic cilia and flagella. We previously identified a CaM and Spoke associated Complex (CSC) and provided evidence that this complex mediates regulatory signals between the radial spokes and dynein arms. We have now used an artificial microRNA (amiRNA) approach to reduce expression of two CSC subunits in Chlamydomonas. For all amiRNA mutants, the entire CSC is lacking or severely reduced in flagella. Structural studies of mutant axonemes revealed that assembly of radial spoke 2 is defective. Furthermore, analysis of both flagellar beating and ...