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University of Massachusetts Medical School Faculty Publications

Cell Biology

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Articles 1 - 16 of 16

Full-Text Articles in Molecular Biology

Identification Of A Novel Invasion-Promoting Region In Insulin Receptor Substrate 2, Jose Mercado-Matos, Jenny Janusis, Sha Zhu, Samuel S. Chen, Leslie M. Shaw Jun 2018

Identification Of A Novel Invasion-Promoting Region In Insulin Receptor Substrate 2, Jose Mercado-Matos, Jenny Janusis, Sha Zhu, Samuel S. Chen, Leslie M. Shaw

University of Massachusetts Medical School Faculty Publications

Although the insulin receptor substrate (IRS) proteins IRS1 and IRS2 share considerable homology and activate common signaling pathways, their contributions to breast cancer are distinct. IRS1 has been implicated in the proliferation and survival of breast tumor cells. In contrast, IRS2 facilitates glycolysis, invasion, and metastasis. To determine the mechanistic basis for IRS2-dependent functions, we investigated unique structural features of IRS2 that are required for invasion. Our studies revealed that the ability of IRS2 to promote invasion is dependent upon upstream insulin-like growth factor 1 receptor (IGF-1R)/insulin receptor (IR) activation and the recruitment and activation of phosphatidylinositol 3-kinase (PI3K ...


Jip1-Mediated Jnk Activation Negatively Regulates Synaptic Plasticity And Spatial Memory, Caroline Morel, Tessi Sherrin, Norman J. Kennedy, Kelly H. Forest, Seda Barutcu, Michael Robles, Ezekiel Carpenter-Hyland, Naghum Alfulaij, Claire L. Standen, Robert A. Nichols, Morris Benveniste, Roger J. Davis, Cedomir Todorovic Apr 2018

Jip1-Mediated Jnk Activation Negatively Regulates Synaptic Plasticity And Spatial Memory, Caroline Morel, Tessi Sherrin, Norman J. Kennedy, Kelly H. Forest, Seda Barutcu, Michael Robles, Ezekiel Carpenter-Hyland, Naghum Alfulaij, Claire L. Standen, Robert A. Nichols, Morris Benveniste, Roger J. Davis, Cedomir Todorovic

University of Massachusetts Medical School Faculty Publications

The c-Jun N-terminal kinase (JNK) signal transduction pathway is implicated in learning and memory. Here, we examined the role of JNK activation mediated by the JIP1 scaffold protein. We compared male wild-type mice with a mouse model harboring a point mutation in the Jip1 gene that selectively blocks JIP1-mediated JNK activation. These male mutant mice exhibited increased NMDA receptor currents, increased NMDA receptor-mediated gene expression, and a lower threshold for induction of hippocampal long-term potentiation. The JIP1 mutant mice also displayed improved hippocampus-dependent spatial memory and enhanced associative fear conditioning. These results were confirmed using a second JIP1 mutant mouse ...


Multiple Molecular Mechanisms Rescue Mtdna Disease In C. Elegans, Suraiya Haroon, Annie Li, Jaye L. Weinert, Clark Fritsch, Nolan G. Ericson, Jasmine Alexander-Floyd, Bart P. Braeckman, Cole M. Haynes, Jason H. Bielas, Tali Gidalevitz, Marc Vermulst Mar 2018

Multiple Molecular Mechanisms Rescue Mtdna Disease In C. Elegans, Suraiya Haroon, Annie Li, Jaye L. Weinert, Clark Fritsch, Nolan G. Ericson, Jasmine Alexander-Floyd, Bart P. Braeckman, Cole M. Haynes, Jason H. Bielas, Tali Gidalevitz, Marc Vermulst

University of Massachusetts Medical School Faculty Publications

Genetic instability of the mitochondrial genome (mtDNA) plays an important role in human aging and disease. Thus far, it has proven difficult to develop successful treatment strategies for diseases that are caused by mtDNA instability. To address this issue, we developed a model of mtDNA disease in the nematode C. elegans, an animal model that can rapidly be screened for genes and biological pathways that reduce mitochondrial pathology. These worms recapitulate all the major hallmarks of mtDNA disease in humans, including increased mtDNA instability, loss of respiration, reduced neuromuscular function, and a shortened lifespan. We found that these phenotypes could ...


Distinct Adipocyte Progenitor Cells Are Associated With Regional Phenotypes Of Perivascular Aortic Fat In Mice, Khanh-Van T. Tran, Timothy P. Fitzgibbons, So Yun Min, Tiffany Desouza, Silvia Corvera Mar 2018

Distinct Adipocyte Progenitor Cells Are Associated With Regional Phenotypes Of Perivascular Aortic Fat In Mice, Khanh-Van T. Tran, Timothy P. Fitzgibbons, So Yun Min, Tiffany Desouza, Silvia Corvera

University of Massachusetts Medical School Faculty Publications

OBJECTIVE: Perivascular adipose tissue depots around the aorta are regionally distinct and have specific functional properties. Thoracic aorta perivascular adipose tissue (tPVAT) expresses higher levels of thermogenic genes and lower levels of inflammatory genes than abdominal aorta perivascular adipose tissue (aPVAT). It is not known whether this distinction is due to the in-vivo functional environment or to cell-autonomous traits that persist outside the in-vivo setting. In this study, we asked whether the progenitor cells in tPVAT and aPVAT have cell-autonomous traits that lead to formation of regionally distinct PVAT.

METHODS: We performed microarray analysis of thoracic and abdominal peri-aortic adipose ...


Upr(Mt) Regulation And Output: A Stress Response Mediated By Mitochondrial-Nuclear Communication, Andrew Melber, Cole M. Haynes Feb 2018

Upr(Mt) Regulation And Output: A Stress Response Mediated By Mitochondrial-Nuclear Communication, Andrew Melber, Cole M. Haynes

University of Massachusetts Medical School Faculty Publications

The mitochondrial network is not only required for the production of energy, essential cofactors and amino acids, but also serves as a signaling hub for innate immune and apoptotic pathways. Multiple mechanisms have evolved to identify and combat mitochondrial dysfunction to maintain the health of the organism. One such pathway is the mitochondrial unfolded protein response (UPR(mt)), which is regulated by the mitochondrial import efficiency of the transcription factor ATFS-1 in C. elegans and potentially orthologous transcription factors in mammals (ATF4, ATF5, CHOP). Upon mitochondrial dysfunction, import of ATFS-1 into mitochondria is reduced, allowing it to be trafficked to ...


Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O'Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres Dec 2017

Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O'Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres

University of Massachusetts Medical School Faculty Publications

Aneuploidy disrupts cellular homeostasis. However, the molecular mechanisms underlying the physiological responses and adaptation to aneuploidy are not well understood. Deciphering these mechanisms is important because aneuploidy is associated with diseases, including intellectual disability and cancer. Although tumors and mammalian aneuploid cells, including several cancer cell lines, show altered levels of sphingolipids, the role of sphingolipids in aneuploidy remains unknown. Here, we show that ceramides and long-chain bases, sphingolipid molecules that slow proliferation and promote survival, are increased by aneuploidy. Sphingolipid levels are tightly linked to serine synthesis, and inhibiting either serine or sphingolipid synthesis can specifically impair the fitness ...


Ki-67 Contributes To Normal Cell Cycle Progression And Inactive X Heterochromatin In P21 Checkpoint-Proficient Human Cells, Xiaoming Sun, Aizhan Bizhanova, Timothy D. Matheson, Jun Yu, Lihua Julie Zhu, Paul D. Kaufman May 2017

Ki-67 Contributes To Normal Cell Cycle Progression And Inactive X Heterochromatin In P21 Checkpoint-Proficient Human Cells, Xiaoming Sun, Aizhan Bizhanova, Timothy D. Matheson, Jun Yu, Lihua Julie Zhu, Paul D. Kaufman

University of Massachusetts Medical School Faculty Publications

Ki-67 protein is widely used as a tumor proliferation marker. However, whether Ki-67 affects cell cycle progression has been controversial. Here, we demonstrate that depletion of Ki-67 in human hTERT-RPE1, WI-38, IMR90, hTERT-BJ cell lines and primary fibroblast cells slowed entry into S phase and coordinately downregulated genes related to DNA replication. Some gene expression changes were partially relieved in Ki-67-depleted hTERT-RPE1 cells by co-depletion of the Rb checkpoint protein, but more thorough suppression of the transcriptional and cell cycle defects was observed upon depletion of cell cycle inhibitor p21. Notably, induction of p21 upon depletion of Ki-67 was a ...


Intraflagellar Transport Protein Ift20 Is Essential For Male Fertility And Spermiogenesis In Mice, Zhengang Zhang, Wei Li, Yong Zhang, Ling Zhang, Maria E. Teves, Hong Liu, Jerome F. Strauss 3rd, Gregory J. Pazour, James A. Foster, Rex A. Hess, Zhibing Zhang Nov 2016

Intraflagellar Transport Protein Ift20 Is Essential For Male Fertility And Spermiogenesis In Mice, Zhengang Zhang, Wei Li, Yong Zhang, Ling Zhang, Maria E. Teves, Hong Liu, Jerome F. Strauss 3rd, Gregory J. Pazour, James A. Foster, Rex A. Hess, Zhibing Zhang

University of Massachusetts Medical School Faculty Publications

Intraflagellar transport (IFT) is a conserved mechanism thought to be essential for the assembly and maintenance of cilia and flagella. However, little is known about its role in mammalian sperm flagella formation. To fill this gap, we disrupted the Ift20 gene in male germ cells. Homozygous mutant mice were infertile with significantly reduced sperm counts and motility. In addition, abnormally shaped elongating spermatid heads and bulbous round spermatids were found in the lumen of the seminiferous tubules. Electron microscopy revealed increased cytoplasmic vesicles, fiber-like structures, abnormal accumulation of mitochondria and a decrease in mature lysosomes. The few developed sperm had ...


Altered Interleukin-10 Signaling In Skeletal Muscle Regulates Obesity-Mediated Inflammation And Insulin Resistance, Sezin Dagdeviren, Dae Young Jung, Eunjung Lee, Randall H. Friedline, Hye Lim Noh, Jong Hun. Kim, Payal R. Patel, Nicholas Tsitsilianos, Andrew V. Tsitsilianos, Duy A. Tran, George H. Tsougranis, Caitlyn C. Kearns, Cecilia P. Uong, Jung Yeon. Kwon, Werner Muller, Ki Won. Lee, Jason K. Kim Nov 2016

Altered Interleukin-10 Signaling In Skeletal Muscle Regulates Obesity-Mediated Inflammation And Insulin Resistance, Sezin Dagdeviren, Dae Young Jung, Eunjung Lee, Randall H. Friedline, Hye Lim Noh, Jong Hun. Kim, Payal R. Patel, Nicholas Tsitsilianos, Andrew V. Tsitsilianos, Duy A. Tran, George H. Tsougranis, Caitlyn C. Kearns, Cecilia P. Uong, Jung Yeon. Kwon, Werner Muller, Ki Won. Lee, Jason K. Kim

University of Massachusetts Medical School Faculty Publications

Skeletal muscle insulin resistance is a major characteristic of obesity and type 2 diabetes. Although obesity-mediated inflammation is causally associated with insulin resistance, the underlying mechanism is unclear. Here, we examined the effects of chronic obesity in mice with muscle-specific overexpression of interleukin-10 (MIL10). After 16 weeks of a high-fat diet (HFD), MIL10 mice became markedly obese but showed improved insulin action compared to that of wild-type mice, which was largely due to increased glucose metabolism and reduced inflammation in skeletal muscle. Since leptin regulates inflammation, the beneficial effects of interleukin-10 (IL-10) were further examined in leptin-deficient ob/ob mice ...


Probability-Based Particle Detection That Enables Threshold-Free And Robust In Vivo Single-Molecule Tracking, Carlas Smith, Sjoerd Stallinga, Keith A. Lidke, Bernd Rieger, David Grunwald Nov 2015

Probability-Based Particle Detection That Enables Threshold-Free And Robust In Vivo Single-Molecule Tracking, Carlas Smith, Sjoerd Stallinga, Keith A. Lidke, Bernd Rieger, David Grunwald

University of Massachusetts Medical School Faculty Publications

Single-molecule detection in fluorescence nanoscopy has become a powerful tool in cell biology but can present vexing issues in image analysis, such as limited signal, unspecific background, empirically set thresholds, image filtering, and false-positive detection limiting overall detection efficiency. Here we present a framework in which expert knowledge and parameter tweaking are replaced with a probability-based hypothesis test. Our method delivers robust and threshold-free signal detection with a defined error estimate and improved detection of weaker signals. The probability value has consequences for downstream data analysis, such as weighing a series of detections and corresponding probabilities, Bayesian propagation of probability ...


A Conserved Flagella-Associated Protein In Chlamydomonas, Fap234, Is Essential For Axonemal Localization Of Tubulin Polyglutamylase Ttll9, Tomohiro Kubo, Haru-Aki Yanagisawa, Zhongmei Liu, Rie Shibuya, Masafumi Hirono, Ritsu Kamiya Jan 2014

A Conserved Flagella-Associated Protein In Chlamydomonas, Fap234, Is Essential For Axonemal Localization Of Tubulin Polyglutamylase Ttll9, Tomohiro Kubo, Haru-Aki Yanagisawa, Zhongmei Liu, Rie Shibuya, Masafumi Hirono, Ritsu Kamiya

University of Massachusetts Medical School Faculty Publications

Tubulin undergoes various posttranslational modifications, including polyglutamylation, which is catalyzed by enzymes belonging to the tubulin tyrosine ligase-like protein (TTLL) family. A previously isolated Chlamydomonas reinhardtii mutant, tpg1, carries a mutation in a gene encoding a homologue of mammalian TTLL9 and displays lowered motility because of decreased polyglutamylation of axonemal tubulin. Here we identify a novel tpg1-like mutant, tpg2, which carries a mutation in the gene encoding FAP234, a flagella-associated protein of unknown function. Immunoprecipitation and sucrose density gradient centrifugation experiments show that FAP234 and TTLL9 form a complex. The mutant tpg1 retains FAP234 in the cell body and flagellar ...


The Dna Damage And The Dna Replication Checkpoints Converge At The Mbf Transcription Factor, Tsvetomira Ivanova, Isabel Alves-Rodrigues, Blanca Gomez-Escoda, Chaitali Dutta, James A. Decaprio, Nicholas R. Rhind, Elena Hidalgo, Jose Ayte Nov 2013

The Dna Damage And The Dna Replication Checkpoints Converge At The Mbf Transcription Factor, Tsvetomira Ivanova, Isabel Alves-Rodrigues, Blanca Gomez-Escoda, Chaitali Dutta, James A. Decaprio, Nicholas R. Rhind, Elena Hidalgo, Jose Ayte

University of Massachusetts Medical School Faculty Publications

In fission yeast cells, Cds1 is the effector kinase of the DNA replication checkpoint. We previously showed that when the DNA replication checkpoint is activated, the repressor Yox1 is phosphorylated and inactivated by Cds1, resulting in activation of MluI-binding factor (MBF)-dependent transcription. This is essential to reinitiate DNA synthesis and for correct G1-to-S transition. Here we show that Cdc10, which is an essential part of the MBF core, is the target of the DNA damage checkpoint. When fission yeast cells are treated with DNA-damaging agents, Chk1 is activated and phosphorylates Cdc10 at its carboxy-terminal domain. This modification is responsible ...


Phosphorylation Of Centromeric Histone H3 Variant Regulates Chromosome Segregation In S. Cerevisiae, Lars Boeckmann, Yoshimitsu Takahashi, Wei-Chun Au, Prashant K. Mishra, John S. Choy, Anthony R. Dawson, May Y. Szeto, Timothy J. Waybright, Christopher Heger, Christopher Mcandrew, Paul K. Goldsmith, Timothy D. Veenstra, Richard E. Baker, Munira A. Basrai Jun 2013

Phosphorylation Of Centromeric Histone H3 Variant Regulates Chromosome Segregation In S. Cerevisiae, Lars Boeckmann, Yoshimitsu Takahashi, Wei-Chun Au, Prashant K. Mishra, John S. Choy, Anthony R. Dawson, May Y. Szeto, Timothy J. Waybright, Christopher Heger, Christopher Mcandrew, Paul K. Goldsmith, Timothy D. Veenstra, Richard E. Baker, Munira A. Basrai

University of Massachusetts Medical School Faculty Publications

The centromeric histone H3 variant (CenH3) is essential for chromosome segregation in eukaryotes. We have identified posttranslational modifications of S. cerevisiae CenH3, Cse4. Functional characterization of cse4 phosphorylation mutants showed growth and chromosome segregation defects when combined with kinetochore mutants okp1 and ame1. Using a phosphoserine-specific antibody we showed that the association of phosphorylated Cse4 with centromeres is increased in response to defective microtubule attachment or reduced cohesion. We determined that evolutionarily conserved Ipl1/Aurora B contributes to phosphorylation of Cse4, as levels of phosphorylated Cse4 were reduced at centromeres in ipl1 strains in vivo and in vitro assays showed ...


Extreme C-Terminal Sites Are Posttranslocationally Glycosylated By The Stt3b Isoform Of The Ost, Shiteshu Shrimal, Steven F. Trueman, Reid Gilmore Apr 2013

Extreme C-Terminal Sites Are Posttranslocationally Glycosylated By The Stt3b Isoform Of The Ost, Shiteshu Shrimal, Steven F. Trueman, Reid Gilmore

University of Massachusetts Medical School Faculty Publications

Metazoan organisms assemble two isoforms of the oligosaccharyltransferase (OST) that have different catalytic subunits (STT3A or STT3B) and partially nonoverlapping roles in asparagine-linked glycosylation. The STT3A isoform of the OST is primarily responsible for co-translational glycosylation of the nascent polypeptide as it enters the lumen of the endoplasmic reticulum. The C-terminal 65-75 residues of a glycoprotein will not contact the translocation channel-associated STT3A isoform of the OST complex before chain termination. Biosynthetic pulse labeling of five human glycoproteins showed that extreme C-terminal glycosylation sites were modified by an STT3B-dependent posttranslocational mechanism. The boundary for STT3B-dependent glycosylation of C-terminal sites was ...


Identification Of Map4k4 As A Novel Suppressor Of Skeletal Muscle Differentiation, Mengxi Wang, Shinya U. Amano, Rachel J. Roth Flach, Anil Chawla, Myriam Aouadi, Michael P. Czech Feb 2013

Identification Of Map4k4 As A Novel Suppressor Of Skeletal Muscle Differentiation, Mengxi Wang, Shinya U. Amano, Rachel J. Roth Flach, Anil Chawla, Myriam Aouadi, Michael P. Czech

University of Massachusetts Medical School Faculty Publications

Myoblast differentiation into mature myotubes is a critical step in the development and repair of human skeletal muscle. Here we show that small interfering RNA (siRNA)-based silencing of the Ste20-like mitogen-activated protein 4 kinase 4 (Map4k4) in C2C12 myoblasts markedly enhances expression of myogenic differentiation genes, myoblast fusion, and myotube diameter. In contrast, adenovirus-mediated expression of native Map4k4 in C2C12 cells attenuates each of these processes, indicating that Map4k4 is a negative regulator of myogenic differentiation and hypertrophy. Expression of a Map4k4 kinase-inactive mutant enhances myotube formation, suggesting that the kinase activity of Map4k4 is essential for its inhibition ...


An Unusual Two-Step Control Of Cpeb Destruction By Pin1, Morris Nechama, Chien-Ling Lin, Joel D. Richter Jan 2013

An Unusual Two-Step Control Of Cpeb Destruction By Pin1, Morris Nechama, Chien-Ling Lin, Joel D. Richter

University of Massachusetts Medical School Faculty Publications

Cytoplasmic polyadenylation is a conserved mechanism that controls mRNA translation and stability. A key protein that promotes polyadenylation-induced translation of mRNAs in maturing Xenopus oocytes is the cytoplasmic polyadenylation element binding protein (CPEB). During this meiotic transition, CPEB is subjected to phosphorylation-dependent ubiquitination and partial destruction, which is necessary for successive waves of polyadenylation of distinct mRNAs. Here we identify the peptidyl-prolyl cis-trans isomerase Pin1 as an important factor mediating CPEB destruction. Pin1 interacts with CPEB in an unusual manner in which it occurs prior to CPEB phosphorylation and prior to Pin1 activation by serine 71 dephosphorylation. Upon induction of ...