Background: Eukaryotic cells are highly compartmentalized by a variety of organelles that carry out specific cellular processes. The position of these organelles within the cell is elaborately regulated and vital for their function. For instance, the position of lysosomes relative to the nucleus controls their degradative capacity and is altered in pathophysiological conditions.
View Article and Find Full Text PDFCells respond to fluctuating nutrient supply by adaptive changes in organelle dynamics and in metabolism. How such changes are orchestrated on a cell-wide scale is unknown. We show that endosomal signaling lipid turnover by MTM1, a phosphatidylinositol 3-phosphate [PI(3)P] 3-phosphatase mutated in X-linked centronuclear myopathy in humans, controls mitochondrial morphology and function by reshaping the endoplasmic reticulum (ER).
View Article and Find Full Text PDFX-linked centronuclear myopathy (XLCNM) is a severe human disease without existing therapies caused by mutations in the phosphoinositide 3-phosphatase MTM1. Loss of MTM1 function is associated with muscle fiber defects characterized by impaired localization of β-integrins and other components of focal adhesions. Here we show that defective focal adhesions and reduced active β-integrin surface levels in a cellular model of XLCNM are rescued by loss of phosphatidylinositiol 3-kinase C2β (PI3KC2β) function.
View Article and Find Full Text PDFIn human cancers, transforming growth factor-β1 (TGF-β1) plays a dual role by acting as both a tumor suppressor and a promoter of tumor metastasis. Although TGF-β1 contributes to the metabolic reprogramming of cancer cells and tumor-associated stromal cells, little is known of the molecular mechanisms connecting this cytokine with enhanced glycolysis. PFKFB3 is a homodymeric bifunctional enzyme, belonging to the family of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases, that controls the conversion of fructose-6-phosphate (Fru-6-P) to fructose-2,6-bisphosphate (Fru-2,6-P ).
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