title: RPTPμ tyrosine phosphatase promotes adipogenic differentiation via modulation of p120 catenin phosphorylation.
abstract: Adipocyte differentiation can be regulated by the combined activity of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). In particular, PTPs act as key regulators in differentiation-associated signaling pathways. We recently found that receptor-type PTPμ (RPTPμ) expression is markedly increased during the adipogenic differentiation of 3T3-L1 preadipocytes and mesenchymal stem cells. Here, we investigate the functional roles of RPTPμ and the mechanism of its involvement in the regulation of signal transduction during adipogenesis of 3T3-L1 cells. Depletion of endogenous RPTPμ by RNA interference significantly inhibited adipogenic differentiation, whereas RPTPμ overexpression led to an increase in adipogenic differentiation. Ectopic expression of p120 catenin suppressed adipocyte differentiation, and the decrease in adipogenesis by p120 catenin was recovered by introducing RPTPμ. Moreover, RPTPμ induced a decrease in the cytoplasmic p120 catenin expression by reducing its tyrosine phosphorylation level, consequently leading to enhanced translocation of Glut-4 to the plasma membrane. On the basis of these results, we propose that RPTPμ acts as a positive regulator of adipogenesis by modulating the cytoplasmic p120 catenin level. Our data conclusively demonstrate that differentiation into adipocytes is controlled by RPTPμ, supporting the utility of RPTPμ and p120 catenin as novel target proteins for the treatment of obesity.
authors: Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea.
authors: Won Kon
authors: WK
authors: Kim
authors: Hyeyun
authors: H
authors: Jung
authors: Eun Young
authors: EY
authors: Kim
authors: Do Hyung
authors: DH
authors: Kim
authors: Yee Sook
authors: YS
authors: Cho
authors: Byoung Chul
authors: BC
authors: Park
authors: Sung Goo
authors: SG
authors: Park
authors: Yong
authors: Y
authors: Ko
authors: Kwang-Hee
authors: KH
authors: Bae
authors: Sang Chul
authors: SC
authors: Lee
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D050156:Adipogenesis / Q000502:physiology*; D000818:Animals; D051177:Catenins / Q000096:biosynthesis* / Q000235:genetics; D002454:Cell Differentiation / Q000502:physiology*; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D010766:Phosphorylation / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D034622:RNA Interference; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2 / Q000235:genetics / Q000378:metabolism*; D000095002:Delta Catenin
chemical_list: D051177:Catenins; D051275:Glucose Transporter Type 4; C495693:Slc2a4 protein, mouse; C516860:Ptprm protein, mouse; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2; D000095002:Delta Catenin; C000722349:Ctnnd1 protein, mouse