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Articles 1 - 5 of 5

Full-Text Articles in Cell Biology

Overlapping Functions Of The Map4k Family Kinases Hppy And Msn In Hippo Signaling, Shuangxi Li, Yong Suk Cho, Tao Yue, Y. Tony Ip, Jin Jiang Nov 2015

Overlapping Functions Of The Map4k Family Kinases Hppy And Msn In Hippo Signaling, Shuangxi Li, Yong Suk Cho, Tao Yue, Y. Tony Ip, Jin Jiang

UMass Center for Clinical and Translational Science Supported Publications

The Hippo (Hpo) tumor suppressor pathway is an evolutionarily conserved signaling pathway that controls tissue growth and organ size in species ranging from Drosophila to human, and its malfunction has been implicated in many types of human cancer. In this study, we conducted a kinome screen and identified Happyhour (Hppy)/MAP4K3 as a novel player in the Hpo pathway. Our biochemical study showed that Hppy binds and phosphorylates Wts. Our genetic experiments suggest that Hppy acts in parallel and partial redundantly with Misshapen (Msn)/MAP4K4 to regulate Yki nuclear localization and Hpo target gene expression in Drosophila wing imaginal discs ...


Centrosome-Intrinsic Mechanisms Modulate Centrosome Integrity During Fever, Anastassiia Vertii, Wendy Zimmerman, Mariya Ivshina, Stephen J. Doxsey Oct 2015

Centrosome-Intrinsic Mechanisms Modulate Centrosome Integrity During Fever, Anastassiia Vertii, Wendy Zimmerman, Mariya Ivshina, Stephen J. Doxsey

UMass Center for Clinical and Translational Science Supported Publications

The centrosome is critical for cell division, ciliogenesis, membrane trafficking, and immunological synapse function. The immunological synapse is part of the immune response, which is often accompanied by fever/heat stress (HS). Here we provide evidence that HS causes deconstruction of all centrosome substructures primarily through degradation by centrosome-associated proteasomes. This renders the centrosome nonfunctional. Heat-activated degradation is centrosome selective, as other nonmembranous organelles (midbody, kinetochore) and membrane-bounded organelles (mitochondria) remain largely intact. Heat-induced centrosome inactivation was rescued by targeting Hsp70 to the centrosome. In contrast, Hsp70 excluded from the centrosome via targeting to membranes failed to rescue, as did ...


Enteroendocrine Cells Support Intestinal Stem-Cell-Mediated Homeostasis In Drosophila, Alla Amcheslavsky, Wei Song, Qi Li, Yingchao Nie, Ivan Bragatto, Dominique Ferrandon, Norbert Perrimon, Y. Tony Ip Oct 2014

Enteroendocrine Cells Support Intestinal Stem-Cell-Mediated Homeostasis In Drosophila, Alla Amcheslavsky, Wei Song, Qi Li, Yingchao Nie, Ivan Bragatto, Dominique Ferrandon, Norbert Perrimon, Y. Tony Ip

UMass Center for Clinical and Translational Science Supported Publications

Intestinal stem cells in the adult Drosophila midgut are regulated by growth factors produced from the surrounding niche cells including enterocytes and visceral muscle. The role of the other major cell type, the secretory enteroendocrine cells, in regulating intestinal stem cells remains unclear. We show here that newly eclosed scute loss-of-function mutant flies are completely devoid of enteroendocrine cells. These enteroendocrine cell-less flies have normal ingestion and fecundity but shorter lifespan. Moreover, in these newly eclosed mutant flies, the diet-stimulated midgut growth that depends on the insulin-like peptide 3 expression in the surrounding muscle is defective. The depletion of Tachykinin-producing ...


Tlr Sorting By Rab11 Endosomes Maintains Intestinal Epithelial-Microbial Homeostasis, Shiyan Yu, Yingchao Nie, Y. Tony Ip, Nan Gao Sep 2014

Tlr Sorting By Rab11 Endosomes Maintains Intestinal Epithelial-Microbial Homeostasis, Shiyan Yu, Yingchao Nie, Y. Tony Ip, Nan Gao

UMass Center for Clinical and Translational Science Supported Publications

Compartmentalization of Toll-like receptors (TLRs) in intestinal epithelial cells (IECs) regulates distinct immune responses to microbes; however, the specific cellular machinery that controls this mechanism has not been fully identified. Here we provide genetic evidences that the recycling endosomal compartment in enterocytes maintains a homeostatic TLR9 intracellular distribution, supporting mucosal tolerance to normal microbiota. Genetic ablation of a recycling endosome resident small GTPase, Rab11a, a gene adjacent to a Crohn's disease risk locus, in mouse IECs and in Drosophila midgut caused epithelial cell-intrinsic cytokine production, inflammatory bowel phenotype, and early mortality. Unlike wild-type controls, germ-free Rab11a-deficient mouse intestines failed ...


Gene Expression Profiling Identifies The Zinc-Finger Protein Charlatan As A Regulator Of Intestinal Stem Cells In Drosophila, Alla Amcheslavsky, Yingchao Nie, Qi Li, Feng He, Leo Tsuda, Michele Markstein, Y. Tony Ip Jul 2014

Gene Expression Profiling Identifies The Zinc-Finger Protein Charlatan As A Regulator Of Intestinal Stem Cells In Drosophila, Alla Amcheslavsky, Yingchao Nie, Qi Li, Feng He, Leo Tsuda, Michele Markstein, Y. Tony Ip

UMass Center for Clinical and Translational Science Supported Publications

Intestinal stem cells (ISCs) in the adult Drosophila midgut can respond to tissue damage and support repair. We used genetic manipulation to increase the number of ISC-like cells in the adult midgut and performed gene expression profiling to identify potential ISC regulators. A detailed analysis of one of these potential regulators, the zinc-finger protein Charlatan, was carried out. MARCM clonal analysis and RNAi in precursor cells showed that loss of Chn function caused severe ISC division defects, including loss of EdU incorporation, phosphorylated histone 3 staining and expression of the mitotic protein Cdc2. Loss of Charlatan also led to a ...