Publications by authors named "Yoav Elkis"

Amino acid (AA) availability is a robust determinant of cell growth through controlling mechanistic/mammalian target of rapamycin complex 1 (mTORC1) activity. According to the predominant model in the field, AA sufficiency drives the recruitment and activation of mTORC1 on the lysosomal surface by the heterodimeric Rag GTPases, from where it coordinates the majority of cellular processes. Importantly, however, the teleonomy of the proposed lysosomal regulation of mTORC1 and where mTORC1 acts on its effector proteins remain enigmatic.

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Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with a high percentage of morbidity. The deciphering and identification of novel targets and tools for intervening with its adverse progression are therefore of immense importance. To address this goal we adopted a specific inhibitor of the intracellular tyrosine kinase Fer, whose expression level is upregulated in PDAC tumors, and is associated with poor prognosis of patients.

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Mucus is made of enormous mucin glycoproteins that polymerize by disulfide crosslinking in the Golgi apparatus. QSOX1 is a catalyst of disulfide bond formation localized to the Golgi. Both QSOX1 and mucins are highly expressed in goblet cells of mucosal tissues, leading to the hypothesis that QSOX1 catalyzes disulfide-mediated mucin polymerization.

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Insulin-regulated glucose homeostasis is a critical and intricate physiological process, of which not all regulatory components have been deciphered. One of the key players in modulating glucose uptake by cells is the glucose transporter-GLUT4. In this study, we aimed to explore the regulatory role of the trans-Golgi-associated protein-TATA Element Modulatory Factor (TMF1) in the GLUT4 mediated, insulin-directed glucose uptake.

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Extracellular matrix (ECM) plays an important role in tumor development and dissemination, but few points of therapeutic intervention targeting ECM of the tumor microenvironment have been exploited to date. Recent observations suggest that the enzymatic introduction of disulfide bond cross-links into the ECM may be modulated to affect cancer progression. Specifically, the disulfide bond-forming activity of the enzyme Quiescin sulfhydryl oxidase 1 (QSOX1) is required by fibroblasts to assemble ECM components for adhesion and migration of cancer cells.

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Disruption of the reprogrammed energy management system of malignant cells is a prioritized goal of targeted cancer therapy. Two regulators of this system are the Fer kinase, and its cancer cell specific variant, FerT, both residing in subcellular compartments including the mitochondrial electron transport chain. Here, we show that a newly developed inhibitor of Fer and FerT, E260, selectively evokes metabolic stress in cancer cells by imposing mitochondrial dysfunction and deformation, and onset of energy-consuming autophagy which decreases the cellular ATP level.

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TMF/ARA160 is known to be a TATA element Modulatory Factor (TMF). It was initially identified as a DNA-binding factor and a coactivator of the Androgen receptor. It was also characterized as a Golgi-associated protein, which is essential for acrosome formation during functional sperm development.

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The kinase Fer and its spermatogenic meiotic variant, FerT, are coexpressed in normal testes and cancerous tumors, but whether they exert related roles in spermatogenic or malignant cells has not been known. Here, we show that Fer and FerT reside in the mitochondria of spermatogenic cells and are harnessed to the reprogrammed mitochondria of colon carcinoma cells. Both kinases bound complex I of the mitochondrial electron transport chain (ETC) in spermatogenic and in colon carcinoma cells, and silencing of either Fer or FerT was sufficient to impair the activity of this complex.

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Tata Element Modulatory Factor (TMF/ARA160) is a multifunctional Golgi-associated protein, which accumulates in colonic enterocytes and goblet cells. Mice lacking TMF/ARA160 (TMF(-/-)) produce thick and uniform colonic mucus that resists adherent bacterial colonization and diminishes susceptibility of these mice to induced acute colitis, through a mechanism that is not fully understood. Here, we show that mucus secretion by goblet cells is altered in the colon of TMF(-/-) mice, resulting in the formation of a highly oligomerized colonic gel-forming mucin, MUC2.

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TMF/ARA160 is a Golgi-associated protein, which is essential for spermiogenesis. In this study, we show that lack of TMF/ARA160 leads to defects in both the testis and the epididymis. In the testis, spermatid retention and extensive proliferation of Leydig cells were observed.

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TMF/ARA160 is a Golgi-associated protein with several cellular functions, among them direction of the NF-κB subunit, p65 RelA, to ubiquitination and proteasomal degradation in stressed cells. We sought to investigate the role of TMF/ARA160 under imposed stress conditions in vivo. TMF(-/-) and wild-type (WT) mice were treated with the ulcerative agent dextran sulfate sodium (DSS), and the severity of the inflicted acute colitis was determined.

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