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University of Massachusetts Medical School

Cellular and Molecular Physiology

2011

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Articles 1 - 10 of 10

Full-Text Articles in Life Sciences

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 ...


Crosstalk Between Ndr Kinase Pathways Coordinates Cell Cycle Dependent Actin Rearrangements, Sneha Gupta, Dannel Mccollum Nov 2011

Crosstalk Between Ndr Kinase Pathways Coordinates Cell Cycle Dependent Actin Rearrangements, Sneha Gupta, Dannel Mccollum

Open Access Articles

Regulation of cytoskeletal remodeling is essential for cell cycle transitions. In fission yeast two NDR kinase signaling cascades, MOR and SIN, regulate the actin cytoskeleton to promote polarized growth during interphase and cytokinesis respectively. Our understanding of how these signaling pathways are coordinated to assist transition between the two cell-cycle stages is limited. Here, we review work from our laboratory, which reveals that cross talk between the SIN and MOR pathways is required for inhibition of interphase polarity programs during cytokinesis. Given the conservation of NDR kinase signaling pathways, our results may define general mechanisms by which these pathways are ...


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 ...


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.


Using Light To Observe And Control Cellular Function: Improving Bioluminescence Imaging And Photocontrol Of Rho Gtpase Activation States: A Dissertation, Katryn R. Harwood Sep 2011

Using Light To Observe And Control Cellular Function: Improving Bioluminescence Imaging And Photocontrol Of Rho Gtpase Activation States: A Dissertation, Katryn R. Harwood

GSBS Dissertations and Theses

The dynamic processes that occur at specific times and locations in cells and/or whole organisms during cellular division, migration, morphogenesis and development are critical. When these molecular events are not properly regulated, disease states can develop. Tools that can allow us to better understand the specific events that, when misregulated, result in disease development can also allow us to determine better ways to combat such misregulation. Specifically, tools that could allow us to better visualize cellular processes or those that allow us to control cellular functioning in a spatiotemporal manner could present great insight into the detailed inner workings ...


High-Resolution Phenotypic Profiling Defines Genes Essential For Mycobacterial Growth And Cholesterol Catabolism, Jennifer E. Griffin, Jeffrey D. Gawronski, Michael A. Dejesus, Thomas R. Ioerger, Brian J. Akerley, Christopher M. Sassetti Sep 2011

High-Resolution Phenotypic Profiling Defines Genes Essential For Mycobacterial Growth And Cholesterol Catabolism, Jennifer E. Griffin, Jeffrey D. Gawronski, Michael A. Dejesus, Thomas R. Ioerger, Brian J. Akerley, Christopher M. Sassetti

GSBS Student Publications

The pathways that comprise cellular metabolism are highly interconnected, and alterations in individual enzymes can have far-reaching effects. As a result, global profiling methods that measure gene expression are of limited value in predicting how the loss of an individual function will affect the cell. In this work, we employed a new method of global phenotypic profiling to directly define the genes required for the growth of Mycobacterium tuberculosis. A combination of high-density mutagenesis and deep-sequencing was used to characterize the composition of complex mutant libraries exposed to different conditions. This allowed the unambiguous identification of the genes that are ...


Requirement Of C-Jun Nh(2)-Terminal Kinase For Ras-Initiated Tumor Formation, Cristina Arrigo Cellurale, Guadalupe Sabio, Norman J. Kennedy, Madhumita Das, Marissa Bylsma, Peter Sandy, Tyler Jacks, Roger J. Davis Apr 2011

Requirement Of C-Jun Nh(2)-Terminal Kinase For Ras-Initiated Tumor Formation, Cristina Arrigo Cellurale, Guadalupe Sabio, Norman J. Kennedy, Madhumita Das, Marissa Bylsma, Peter Sandy, Tyler Jacks, Roger J. Davis

Davis Lab Publications

The c-Jun NH(2)-terminal kinase (JNK) signal transduction pathway causes increased gene expression mediated, in part, by members of the activating transcription factor protein (AP1) group. JNK is therefore implicated in the regulation of cell growth and cancer. To test the role of JNK in Ras-induced tumor formation, we examined the effect of compound ablation of the ubiquitously expressed genes Jnk1 plus Jnk2. We report that JNK is required for Ras-induced transformation of p53-deficient primary cells in vitro. Moreover, JNK is required for lung tumor development caused by mutational activation of the endogenous KRas gene in vivo. Together, these ...


The Role Of Jnk In The Development Of Hepatocellular Carcinoma, Madhumita Das, David S. Garlick, Dale Greiner, Roger J. Davis Mar 2011

The Role Of Jnk In The Development Of Hepatocellular Carcinoma, Madhumita Das, David S. Garlick, Dale Greiner, Roger J. Davis

Davis Lab Publications

The cJun NH(2)-terminal kinase (JNK) signal transduction pathway has been implicated in the growth of carcinogen-induced hepatocellular carcinoma. However, the mechanism that accounts for JNK-regulated tumor growth is unclear. Here we demonstrate that compound deficiency of the two ubiquitously expressed JNK isoforms (JNK1 and JNK2) in hepatocytes does not prevent hepatocellular carcinoma development. Indeed, JNK deficiency in hepatocytes increased the tumor burden. In contrast, compound JNK deficiency in hepatocytes and nonparenchymal cells reduced both hepatic inflammation and tumorigenesis. These data indicate that JNK plays a dual role in the development of hepatocellular carcinoma. JNK promotes an inflammatory hepatic ...


Jnk Regulates Foxo-Dependent Autophagy In Neurons, Ping Xu, Madhumita Das, Judith Reilly, Roger J. Davis Feb 2011

Jnk Regulates Foxo-Dependent Autophagy In Neurons, Ping Xu, Madhumita Das, Judith Reilly, Roger J. Davis

Davis Lab Publications

The cJun N-terminal kinase (JNK) signal transduction pathway is implicated in the regulation of neuronal function. JNK is encoded by three genes that play partially redundant roles. Here we report the creation of mice with targeted ablation of all three Jnk genes in neurons. Compound JNK-deficient neurons are dependent on autophagy for survival. This autophagic response is caused by FoxO-induced expression of Bnip3 that displaces the autophagic effector Beclin-1 from inactive Bcl-XL complexes. These data identify JNK as a potent negative regulator of FoxO-dependent autophagy in neurons.


Regulation Of Senescence In Cancer And Aging, Yahui Kong, Hang Cui, Charusheila Ramkumar, Hong Zhang Jan 2011

Regulation Of Senescence In Cancer And Aging, Yahui Kong, Hang Cui, Charusheila Ramkumar, Hong Zhang

Zhang Lab Publications

Senescence is regarded as a physiological response of cells to stress, including telomere dysfunction, aberrant oncogenic activation, DNA damage, and oxidative stress. This stress response has an antagonistically pleiotropic effect to organisms: beneficial as a tumor suppressor, but detrimental by contributing to aging. The emergence of senescence as an effective tumor suppression mechanism is highlighted by recent demonstration that senescence prevents proliferation of cells at risk of neoplastic transformation. Consequently, induction of senescence is recognized as a potential treatment of cancer. Substantial evidence also suggests that senescence plays an important role in aging, particularly in aging of stem cells. In ...