Open Access. Powered by Scholars. Published by Universities.®

Biochemistry, Biophysics, and Structural Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 30

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

Molecular Targets Of Apigenin In Colorectal Cancer Cells: Involvement Of P21, Nag-1 And P53., Yi Zhong, C Krisanapun, Seong-Ho Lee, T Nualsanit, C Sams, P Peungvicha, Seung Baek Nov 2010

Molecular Targets Of Apigenin In Colorectal Cancer Cells: Involvement Of P21, Nag-1 And P53., Yi Zhong, C Krisanapun, Seong-Ho Lee, T Nualsanit, C Sams, P Peungvicha, Seung Baek

Seung J Baek

Persuasive epidemiological and experimental evidence suggests that dietary flavonoids have anti-cancer activity. Since conventional therapeutic and surgical approaches have not been able to fully control the incidence and outcome of most cancer types, including colorectal neoplasia, there is an urgent need to develop alternative approaches for the management of cancer. We sought to develop the best flavonoids for the inhibition of cell growth, and apigenin (flavone) proved the most promising compound in colorectal cancer cell growth arrest. Subsequently, we found that pro-apoptotic proteins (NAG-1 and p53) and cell cycle inhibitor (p21) were induced in the presence of apigenin, and kinase ...


Feronia Receptor-Like Kinase Regulates Rho Gtpase Signaling Of Root Hair Development, Q. Duan, D. Kita, C. Li, Alice Cheung, H. M. Wu Oct 2010

Feronia Receptor-Like Kinase Regulates Rho Gtpase Signaling Of Root Hair Development, Q. Duan, D. Kita, C. Li, Alice Cheung, H. M. Wu

Alice Cheung

Plant RHO GTPases (RAC/ROPs) mediate multiple extracellular signals ranging from hormone to stress and regulate diverse cellular processes important for polarized cell growth, differentiation, development, reproduction, and responses to the environment. They shuttle between the GDP-bound inactive state and the GTP-bound activated state and their activation is predominantly mediated by a family of guanine nucleotide exchange factors (GEFs) referred to as ROPGEFs. Using the Arabidopsis ROPGEF1 as bait, we identified members of a receptor-like kinase (RLK) family as potential upstream regulators for RAC/ROP signaling. NADPH oxidase-derived reactive oxygen species (ROS) are emerging as important regulators for growth and ...


Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek Oct 2010

Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek

Maria Cekanova MS, RNDr, PhD

Peroxisome proliferator-activated receptor gamma (PPARgamma) plays a central role in cell differentiation, metabolism and tumorigenesis. We have investigated the therapeutic properties of 5-[[6-[(2-fluorophenyl)-methoxy]-2-napthalenyl]-methyl]-2,4-thiazolidinedione (MCC-555) a PPARgamma agonist in human colorectal cancer cells. To elucidate the molecular mechanism(s), by which MCC-555 exerts its effects on the human colorectal cancer cells, we have analyzed the expression of two pro-apoptotic proteins, Krüppel-like factor 4 (KLF4) and nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1). MCC-555-induced expression of the transcription factor, KLF-4 was blocked by a PPARgamma specific antagonist GW9662 in PPARgamma-dependent manner in HCT-116 cells. We ...


Mechanistic And Signaling Analysis Of Muc4-Erbb2 Signaling Module: New Insights Into The Mechanism Of Ligand-Independent Erbb2 Activity, Goldi Kozloski Sep 2010

Mechanistic And Signaling Analysis Of Muc4-Erbb2 Signaling Module: New Insights Into The Mechanism Of Ligand-Independent Erbb2 Activity, Goldi Kozloski

Goldi A Kozloski

The membrane mucin Muc4 is aberrantly expressed in numerous epithelial carcinomas and is currently used as a cancer diagnostic and prognostic tool. Muc4 can also potentiate signal transduction by modulating differential ErbB2 phosphorylation in the absence and in the presence of the ErbB3 soluble ligand heregulin (HRG-beta1). These features of Muc4 suggest that Muc4 is not merely a cancer marker, but an oncogenic factor with a unique-binding/activation relationship with the receptor ErbB2. In the present study, we examined the signaling mechanisms that are associated with the Muc4-ErbB2 module by analyzing ErbB2 differential signaling in response to Muc4 expression. Our ...


An Interdomain Sector Mediating Allostery In Hsp70 Molecular Chaperones, Robert Smock, Olivier Rivoire, William Russ, Joanna Swain, Stanislas Leibler, Rama Ranganathan, Lila Gierasch Sep 2010

An Interdomain Sector Mediating Allostery In Hsp70 Molecular Chaperones, Robert Smock, Olivier Rivoire, William Russ, Joanna Swain, Stanislas Leibler, Rama Ranganathan, Lila Gierasch

Lila Gierasch

Allosteric coupling between protein domains is fundamental to many cellular processes. For example, Hsp70 molecular chaperones use ATP binding by their actin-like N-terminal ATPase domain to control substrate interactions in their C-terminal substrate-binding domain, a reaction that is critical for protein folding in cells. Here, we generalize the statistical coupling analysis to simultaneously evaluate co-evolution between protein residues and functional divergence between sequences in protein sub-families. Applying this method in the Hsp70/110 protein family, we identify a sparse but structurally contiguous group of co-evolving residues called a ‘sector’, which is an attribute of the allosteric Hsp70 sub-family that links ...


Role Of Hsp70 Atpase Domain Intrinsic Dynamics And Sequence Evolution In Enabling Its Functional Interactions With Nefs, Ying Liu, Lila Gierasch, Ivet Bahar Sep 2010

Role Of Hsp70 Atpase Domain Intrinsic Dynamics And Sequence Evolution In Enabling Its Functional Interactions With Nefs, Ying Liu, Lila Gierasch, Ivet Bahar

Lila Gierasch

12 Hide Figures Abstract Author Summary Introduction Materials and Methods Results Discussion Supporting Information Acknowledgments Author Contributions References Reader Comments (0) Figures Abstract Catalysis of ADP-ATP exchange by nucleotide exchange factors (NEFs) is central to the activity of Hsp70 molecular chaperones. Yet, the mechanism of interaction of this family of chaperones with NEFs is not well understood in the context of the sequence evolution and structural dynamics of Hsp70 ATPase domains. We studied the interactions of Hsp70 ATPase domains with four different NEFs on the basis of the evolutionary trace and co-evolution of the ATPase domain sequence, combined with elastic ...


Epicatechin Gallate Suppresses Oxidative Stress-Induced Muc5ac Overexpression By Interaction With Epidermal Growth Factor Receptor, Hj Kim, Jh Ryu, Ch Kim, Jw Lim, Uy Moon, Gh Lee, Seung Baek, Jh Yoon Aug 2010

Epicatechin Gallate Suppresses Oxidative Stress-Induced Muc5ac Overexpression By Interaction With Epidermal Growth Factor Receptor, Hj Kim, Jh Ryu, Ch Kim, Jw Lim, Uy Moon, Gh Lee, Seung Baek, Jh Yoon

Seung J Baek

The goal of this study was to investigate the effect of epicatechin gallate (ECG), a component of green tea polyphenols, on the signal pathway for oxidative stress-induced intracellular reactive oxygen species (ROS) generation and MUC5AC overexpression in normal human nasal epithelial (NHNE) cells. Passage-2 NHNE cells were used, and ECG was administered before stimulation with exogenous hydrogen peroxide (H(2)O(2)). MUC5AC gene and protein levels were measured by real-time PCR and dot blot analysis. Western blot analysis and immunocytofluorescence study were performed for detecting the activity of epidermal growth factor receptor (EGFR). Exogenous H(2)O(2) increases ...


Activating Transcription Factor 2 (Atf2) Controls Tolfenamic Acid-Induced Atf3 Expression Via Map Kinase Pathways., Seong-Ho Lee, Jae Hoon Bahn, Nichelle Whitlock, Seung Baek Aug 2010

Activating Transcription Factor 2 (Atf2) Controls Tolfenamic Acid-Induced Atf3 Expression Via Map Kinase Pathways., Seong-Ho Lee, Jae Hoon Bahn, Nichelle Whitlock, Seung Baek

Seung J Baek

Tolfenamic acid (TA) is a non-steroidal anti-inflammatory drug associated with anti-tumorigenic and pro-apoptotic properties in animal and in vitro models of cancer. However, the underlying cellular mechanisms by which TA exerts its effects are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/CREB subfamily of the basic region-leucine zipper family and has been known as a tumor suppressor in human colorectal cancer cells. The present study was performed to observe whether ATF3 mediates TA-induced apoptosis and to elucidate the molecular mechanism of ATF3 transcription induced by TA. TA treatment and ectopic expression of ATF3 ...


Autonomous Bioluminescent Expression Of The Bacterial Luciferase Gene Cassette (Lux) In A Mammalian Cell Line, Dan Close, Patterson, Ripp, Seung Baek, Sanseverino, Gary Sayler Jul 2010

Autonomous Bioluminescent Expression Of The Bacterial Luciferase Gene Cassette (Lux) In A Mammalian Cell Line, Dan Close, Patterson, Ripp, Seung Baek, Sanseverino, Gary Sayler

Seung J Baek

No abstract provided.


(-)-Epigallocatechin-3-Gallate (Egcg) Post-Transcriptionally And Post-Translationally Suppresses The Cell Proliferative Protein Trop2 In Human Colorectal Cancer Cells., Seung Baek, Mugdha Sukhthankar, Saverio Alberti Jul 2010

(-)-Epigallocatechin-3-Gallate (Egcg) Post-Transcriptionally And Post-Translationally Suppresses The Cell Proliferative Protein Trop2 In Human Colorectal Cancer Cells., Seung Baek, Mugdha Sukhthankar, Saverio Alberti

Seung J Baek

BACKGROUND: TROP-2 is a tumor-promoting molecule that has been found to be overexpressed in many cancer cells, making it a plausible biomarker of carcinogenesis. The main aim of this study was to examine the effect of green tea catechins (namely, (-)-epigallocatechin-3-gallate; EGCG) on TROP-2 expression. MATERIALS AND METHODS: Western blot and RT-PCR were applied to assess TROP2 expression in colorectal cancer cells and tissues. RESULTS: Two different mechanisms were found to operate in diverse cell lines. In SW480 cells, EGCG affected the post-transcriptional processing of the TROP-2 mRNA, as this was quickly and specifically degraded in the presence of EGCG ...


Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek Jul 2010

Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek

Seong-Ho Lee

Peroxisome proliferator-activated receptor gamma (PPARgamma) plays a central role in cell differentiation, metabolism and tumorigenesis. We have investigated the therapeutic properties of 5-[[6-[(2-fluorophenyl)-methoxy]-2-napthalenyl]-methyl]-2,4-thiazolidinedione (MCC-555) a PPARgamma agonist in human colorectal cancer cells. To elucidate the molecular mechanism(s), by which MCC-555 exerts its effects on the human colorectal cancer cells, we have analyzed the expression of two pro-apoptotic proteins, Krüppel-like factor 4 (KLF4) and nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1). MCC-555-induced expression of the transcription factor, KLF-4 was blocked by a PPARgamma specific antagonist GW9662 in PPARgamma-dependent manner in HCT-116 cells. We ...


Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek Jun 2010

Mcc-555-Induced Nag-1 Expression Is Mediated In Part By Klf4., Maria Cekanova, Seong-Ho Lee, Michael Mcentee, Seung Baek

Seung J Baek

Peroxisome proliferator-activated receptor gamma (PPARgamma) plays a central role in cell differentiation, metabolism and tumorigenesis. We have investigated the therapeutic properties of 5-[[6-[(2-fluorophenyl)-methoxy]-2-napthalenyl]-methyl]-2,4-thiazolidinedione (MCC-555) a PPARgamma agonist in human colorectal cancer cells. To elucidate the molecular mechanism(s), by which MCC-555 exerts its effects on the human colorectal cancer cells, we have analyzed the expression of two pro-apoptotic proteins, Krüppel-like factor 4 (KLF4) and nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1). MCC-555-induced expression of the transcription factor, KLF-4 was blocked by a PPARgamma specific antagonist GW9662 in PPARgamma-dependent manner in HCT-116 cells. We ...


Rna Processing Of Nitrogenase Transcripts In The Cyanobacterium Anabaena Variabilis, Justin L. Ungerer, Brenda S. Pratte, Teresa Thiel Jun 2010

Rna Processing Of Nitrogenase Transcripts In The Cyanobacterium Anabaena Variabilis, Justin L. Ungerer, Brenda S. Pratte, Teresa Thiel

Teresa Thiel

Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied by using a lacZ reporter. Despite evidence for a transcription start site just upstream of nifH1 and vnfH, promoter fragments that included these start sites did not drive the transcription of lacZ and, for nifH1, did not drive the expression of nifHDK1. Further analysis using larger regions upstream of nifH1 indicated that a promoter within nifU1 and a promoter upstream of nifB1 both contributed to expression of nifHDK1 ...


Effects Of Atmospheric Non-Thermal Plasma On Invasion Of Colorectal Cancer Cells., Seung Baek, Chul-Ho Kim, S Kwon, K Lee, S Jun, Philip Rack May 2010

Effects Of Atmospheric Non-Thermal Plasma On Invasion Of Colorectal Cancer Cells., Seung Baek, Chul-Ho Kim, S Kwon, K Lee, S Jun, Philip Rack

Seung J Baek

No abstract provided.


Molecular Basis For Distinct Pathways For Protein Import Into Arabidopsis Chloroplasts, Danny Schnell, C. Rounds, H. Inoue May 2010

Molecular Basis For Distinct Pathways For Protein Import Into Arabidopsis Chloroplasts, Danny Schnell, C. Rounds, H. Inoue

Danny Schnell

The translocons at the outer envelope membrane of chloroplasts (TOCs) initiate the import of thousands of nucleus-encoded proteins into the organelle. The identification of structurally and functionally distinct TOC complexes has led to the hypothesis that the translocons constitute different import pathways that are required to coordinate the import of sets of proteins whose expression varies in response to organelle biogenesis and physiological adaptation. To test this hypothesis, we examined the molecular basis for distinct TOC pathways by analyzing the functional diversification among the Toc159 family of TOC receptors. We demonstrate that the N-terminal A-domains of the Toc159 receptors regulate ...


Human Monocytes, Macrophages, And Dendritic Cells: Alcohol Treatment Methods, Gyongyi Szabo, Pranoti Mandrekar Apr 2010

Human Monocytes, Macrophages, And Dendritic Cells: Alcohol Treatment Methods, Gyongyi Szabo, Pranoti Mandrekar

Gyongyi Szabo

Both acute and chronic alcohol consumption have significant immunomodulatory effects of which alterations in innate immune functions contribute to impaired antimicrobial defense and inflammatory responses. Blood monocytes, macrophages, and dendritic cells play a central role in innate immune recognition as these cells recognize pathogens, respond with inflammatory cytokine production, and induce antigen-specific T-lymphocyte activation. All of these innate immune cell functions are affected in humans by alcohol intake. Here, we summarize the different effects of acute and chronic alcohol on monocyte, macrophage, and dendritic cell functions in humans and describe methods for separation and functional evaluation of these cell types.


Determinants For Stop-Transfer And Post-Import Pathways For Protein Targeting To The Chloroplast Inner Envelope Membrane, Antonio A. B. Viana, Ming Li, Danny Schnell Apr 2010

Determinants For Stop-Transfer And Post-Import Pathways For Protein Targeting To The Chloroplast Inner Envelope Membrane, Antonio A. B. Viana, Ming Li, Danny Schnell

Danny Schnell

he inner envelope membrane (IEM) of the chloroplast plays key roles in controlling metabolite transport between the organelle and cytoplasm and is a major site of lipid and membrane synthesis within the organelle. IEM biogenesis requires the import and integration of nucleus-encoded membrane proteins. Previous reports have led to the conclusion that membrane proteins are inserted into the IEM during protein import from the cytoplasm via a stop-transfer mechanism or are completely imported into the stroma and then inserted into the IEM in a post-import mechanism. In this study, we examined the determinants for each pathway by comparing the targeting ...


An Entrepreneurial Approach To Librarianship, Flora G. Shrode, Jennifer R. Duncan, Wendy Holliday Apr 2010

An Entrepreneurial Approach To Librarianship, Flora G. Shrode, Jennifer R. Duncan, Wendy Holliday

Flora Shrode

Librarians from Utah State University explain recent efforts to encourage subject librarians to take a more holistic view of their roles. We are shifting from a traditional emphasis primarily on collection development and refocusing on natural connections between collections, instruction, liaison, and reference service. The poster provides background about Utah State University’s situation and explains our approach to analyzing local needs and culture to inform development of a new organizational structure. We describe our vision of subject librarianship, the process by which we assessed librarians’ ideas and goals for performing as subject librarians, and the actions we are taking ...


Systematic Discovery Of Regulatory Motifs In Fusarium Graminearum By Comparing Four Fusarium Genomes, Lokesh Kumar, Andrew Breakspear, Corby Kistler, Li-Jun Ma, Xiaohui Xie Mar 2010

Systematic Discovery Of Regulatory Motifs In Fusarium Graminearum By Comparing Four Fusarium Genomes, Lokesh Kumar, Andrew Breakspear, Corby Kistler, Li-Jun Ma, Xiaohui Xie

Li-Jun Ma

Background

Fusarium graminearum (Fg), a major fungal pathogen of cultivated cereals, is responsible for billions of dollars in agriculture losses. There is a growing interest in understanding the transcriptional regulation of this organism, especially the regulation of genes underlying its pathogenicity. The generation of whole genome sequence assemblies for Fg and three closely related Fusarium species provides a unique opportunity for such a study.

Results

Applying comparative genomics approaches, we developed a computational pipeline to systematically discover evolutionarily conserved regulatory motifs in the promoter, downstream and the intronic regions of Fg genes, based on the multiple alignments of sequenced Fusarium ...


Antimicrobial And Antioxidant Activities Of Essential Oil And Methanol Extract Of Jasminum Sambac From Djibouti, Fatou Abdoul-Latif, Prosper Edou, François Eba, Nabil Mohamed, Adwa Ali, Samatar Djama, Louis-Clément Obame, Mamoudou Hama Dicko Mar 2010

Antimicrobial And Antioxidant Activities Of Essential Oil And Methanol Extract Of Jasminum Sambac From Djibouti, Fatou Abdoul-Latif, Prosper Edou, François Eba, Nabil Mohamed, Adwa Ali, Samatar Djama, Louis-Clément Obame, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The essential oil of jasminum sambac from Djibouti was subjected to screening for their possible antioxidant activity by two complementary test systems, namely DPPH free radical scavenging and beta-carotene-linoleic acid assays. Butylated hydroxytoluene (BHT) was used as positive control in both test systems. In the DPPH test system, the IC50 value of essential oil and methanol extract were respectively 7.43 and 2.30 μg/ml. In the beta-carotene-linoleic acid system, oxidation was effectively inhibited by Jasminum sambac, the RAA value of essential oil and methanol extract were respectively 96.6 and 93.9%. When compared to BHT, the essential ...


Putting Metal In The Middle, David Bollivar Mar 2010

Putting Metal In The Middle, David Bollivar

David Bollivar

Placing metal ions into the center of a porphyrin ring is a significant cellular challenge. Lundqvist et ai. (2010) provide snapshots of the AAA + motor unit of magnesium chelatase, an enzyme that insert magnesium ion into the porphyrin ring accompanied by ATP expenditure, in different states of binding to adenosyl nucleotides.


Large Scale Reverse Genetics In Arabidopsis: Case Studies From The Chloroplast 2010 Project, Imad Ajjawi, Yan Lu, Linda Savage, Shannon Bell, Robert Last Jan 2010

Large Scale Reverse Genetics In Arabidopsis: Case Studies From The Chloroplast 2010 Project, Imad Ajjawi, Yan Lu, Linda Savage, Shannon Bell, Robert Last

Yan Lu

No abstract provided.


Myosin Xi Is Essential For Tip Growth In Physcomitrella Patens, L Vidali, Gm Burkart, Rc Augustine, E Kerdavid, E Tuzel, M Bezanilla Jan 2010

Myosin Xi Is Essential For Tip Growth In Physcomitrella Patens, L Vidali, Gm Burkart, Rc Augustine, E Kerdavid, E Tuzel, M Bezanilla

Magdalena Bezanilla

Class XI myosins are plant specific and responsible for cytoplasmic streaming. Because of the large number of myosin XI genes in angiosperms, it has been difficult to determine their precise role, particularly with respect to tip growth. The moss Physcomitrella patens provides an ideal system to study myosin XI function. P. patens has only two myosin XI genes, and these genes encode proteins that are 94% identical to each other. To determine their role in tip growth, we used RNA interference to specifically silence each myosin XI gene using 5′ untranslated region sequences. We discovered that the two myosin XI ...


Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Brad Binder, Yi-Feng Chen, Zhiyong Gao, Robert Kerris, Wuyi Wang, G. Schaller Dec 2009

Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Brad Binder, Yi-Feng Chen, Zhiyong Gao, Robert Kerris, Wuyi Wang, G. Schaller

Brad M. Binder

Background The gaseous plant hormone ethylene is perceived in Arabidopsis thaliana by a five-member receptor family composed of ETR1, ERS1, ETR2, ERS2, and EIN4. Methodology/Principal Findings Gel-filtration analysis of ethylene receptors solubilized from Arabidopsis membranes demonstrates that the receptors exist as components of high-molecular-mass protein complexes. The ERS1 protein complex exhibits an ethylene-induced change in size consistent with ligand-mediated nucleation of protein-protein interactions. Deletion analysis supports the participation of multiple domains from ETR1 in formation of the protein complex, and also demonstrates that targeting to and retention of ETR1 at the endoplasmic reticulum only requires the first 147 amino ...


Cell Adhesion Property Affected By Cyclooxygenase And Lipoxygenase: Opto-Electric Approach (With Chang Kyoung Choi, Mugdha Sukhthankar, Chul-Ho Kim, Seong-Ho Lee, Anthony English, Kenneth D. Kihm., Seung Baek Dec 2009

Cell Adhesion Property Affected By Cyclooxygenase And Lipoxygenase: Opto-Electric Approach (With Chang Kyoung Choi, Mugdha Sukhthankar, Chul-Ho Kim, Seong-Ho Lee, Anthony English, Kenneth D. Kihm., Seung Baek

Seung J Baek

Expression of cyclooxygenases (COX) and lipoxygenases (LOX) has been linked to many pathophysiological phenotypes, including cell adhesion. However, many current approaches to measure cellular changes are performed only in a fixed-time point. Since cells dynamically move in conjunction with the cell matrix, there is a pressing need for dynamic or time-dependent methods for the investigation of cell properties. In the presented study, we used stable human colorectal cancer cell lines ectopically expressing COX-1, COX-2, and 15LOX-1, to investigate whether expression of COX-1, COX-2, or 15LOX-1 would affect cell adhesion using our opto-electric methodology. In a fixed-time point experiment, only COX-1- ...


Nsaid-Activated Gene-1 As A Molecular Target For Capsaicin-Induced Apoptosis Through A Novel Molecular Mechanism Involving Gsk3beta, C/Ebpbeta And Atf3, Seung Baek, Seong-Ho Lee, Chutwadee Krisanapun Dec 2009

Nsaid-Activated Gene-1 As A Molecular Target For Capsaicin-Induced Apoptosis Through A Novel Molecular Mechanism Involving Gsk3beta, C/Ebpbeta And Atf3, Seung Baek, Seong-Ho Lee, Chutwadee Krisanapun

Seung J Baek

Capsaicin, a natural product of the Capsicum species of red peppers, is known to induce apoptosis and suppress growth. Non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) is a cytokine associated with pro-apoptotic and antitumorigenic property in colorectal and lung cancer. Our data demonstrate that capsaicin leads to induction of apoptosis and up-regulates NAG-1 gene expression at the transcriptional level. Overexpression of CCAAT/enhancer binding protein beta (C/EBPbeta) caused a significant increase of basal and capsaicin-induced NAG-1 promoter activity. We subsequently identified C/EBPbeta binding sites in the NAG-1 promoter responsible for capsaicin-induced NAG-1 transactivation. Electrophoretic mobility shift assay and chromatin immunoprecipitation ...


A Potential Proliferative Gene, Nudt6, Is Down-Regulated By Green Tea Catechins At The Posttranscriptional Level, Seung Baek, Mugdha Sukthankar, Ck Choi, A English, Js Kim Dec 2009

A Potential Proliferative Gene, Nudt6, Is Down-Regulated By Green Tea Catechins At The Posttranscriptional Level, Seung Baek, Mugdha Sukthankar, Ck Choi, A English, Js Kim

Seung J Baek

The main aims of this study were to elucidate the effect of green tea catechins on Nudix-type motif 6 (NUDT6) suppression and to characterize NUDT6's biological activity. Our microarray data showed that the green tea component epicatechin-3-gallate suppressed NUDT6 expression, and this was confirmed by RT-PCR. Subsequently, the use of different catechins showed that the effect of epigallocatechin-3-gallate (EGCG) was stronger than that of other catechins. At the posttranscriptional level, EGCG decreased the RNA stability of NUDT6, indicating it as a potential mechanism of NUDT6 suppression. Further cloning of the 3' untranslated region of human NUDT6 mRNA resulted in ...


In Vitro Anti-Proliferative Activity Of Alcoholic Stem Extract Of Coscinium Fenestratum In Human Colorectal Cancer Cells, P Rojsanga, M Sukthankar, C Krisanapun, W Gritsanapan, D Lawson, Seung Baek Dec 2009

In Vitro Anti-Proliferative Activity Of Alcoholic Stem Extract Of Coscinium Fenestratum In Human Colorectal Cancer Cells, P Rojsanga, M Sukthankar, C Krisanapun, W Gritsanapan, D Lawson, Seung Baek

Seung J Baek

Coscinium fenestratum (Gaertn.) Colebr. is traditionally used for the treatment of cancer, arthritis and diabetes mellitus. The purpose of this study was to determine the molecular mechanisms by which this plant shows beneficial effects. An 80% ethanolic extract of C. fenestratum (80ET) was separated by its polarity into dichloromethane (DCM) and aqueous fractions (WF), and the anti-proliferative effects of 80ET, DCM and WF were investigated. Berberine, one of the major components of C. fenestratum, was used as a control. The 80ET, DCM, WF and berberine showed anti-proliferative activity as assessed by cell growth assay. Subsequently, the pro-apoptotic proteins NAG-1 and ...


The 1.9 Å Structure Of Human Α-N-Acetylgalactosaminidase The Molecular Basis Of Schindler And Kanzaki Diseases, Nathaniel E. Clark, Scott Garman Dec 2009

The 1.9 Å Structure Of Human Α-N-Acetylgalactosaminidase The Molecular Basis Of Schindler And Kanzaki Diseases, Nathaniel E. Clark, Scott Garman

Scott Garman

alpha-N-acetylgalactosaminidase (alpha-NAGAL; E.C. 3.2.1.49) is a lysosomal exoglycosidase that cleaves terminal alpha-N-acetylgalactosamine residues from glycopeptides and glycolipids. In humans, a deficiency of alpha-NAGAL activity results in the lysosomal storage disorders Schindler disease and Kanzaki disease. To better understand the molecular defects in the diseases, we determined the crystal structure of human alpha-NAGAL after expressing wild-type and glycosylation-deficient glycoproteins in recombinant insect cell expression systems. We measured the enzymatic parameters of our purified wild-type and mutant enzymes, establishing their enzymatic equivalence. To investigate the binding specificity and catalytic mechanism of the human alpha-NAGAL enzyme, we determined three ...


Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Yi-Feng Chen, Zhiyong Gao, Robert J. Kerriss Iii, Wuyi Wang, Brad M. Binder, G. Eric Schaller Dec 2009

Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Yi-Feng Chen, Zhiyong Gao, Robert J. Kerriss Iii, Wuyi Wang, Brad M. Binder, G. Eric Schaller

Brad M. Binder

The gaseous plant hormone ethylene is perceived in Arabidopsis thaliana by a five-member receptor family composed of ETR1, ERS1, ETR2, ERS2, and EIN4. Methodology/Principal Findings Gel-filtration analysis of ethylene receptors solubilized from Arabidopsis membranes demonstrates that the receptors exist as components of high-molecular-mass protein complexes. The ERS1 protein complex exhibits an ethylene-induced change in size consistent with ligand-mediated nucleation of protein-protein interactions. Deletion analysis supports the participation of multiple domains from ETR1 in formation of the protein complex, and also demonstrates that targeting to and retention of ETR1 at the endoplasmic reticulum only requires the first 147 amino acids ...