title: FAM122A, a new endogenous inhibitor of protein phosphatase 2A.
abstract: The regulation of the ubiquitously expressed protein phosphatase 2A (PP2A) is essential for various cellular functions such as cell proliferation, transformation, and fate determination. In this study, we demonstrate that the highly conserved protein in mammals, designated FAM122A, directly interacts with PP2A-Aα and B55α rather than B56α subunits, and inhibits the phosphatase activity of PP2A-Aα/B55α/Cα complex. Further, FAM122A potentiates the degradation of catalytic subunit PP2A-Cα with the increased poly-ubiquitination. In agreement, FAM122A silencing inhibits while its overexpression enhances cell growth and colony-forming ability. Collectively, we identify FAM122A as a new endogenous PP2A inhibitor and its physiological and pathophysiological significances warrant to be further investigated.
authors: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Li
authors: L
authors: Fan
authors: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Man-Hua
authors: MH
authors: Liu
authors: Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Meng
authors: M
authors: Guo
authors: Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Chuan-Xi
authors: CX
authors: Hu
authors: Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Zhao-Wen
authors: ZW
authors: Yan
authors: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Jing
authors: J
authors: Chen
authors: Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.|Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Guo-Qiang
authors: GQ
authors: Chen
authors: Institute of Health Sciences, Shanghai Institutes for Biological Sciences of Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Ying
authors: Y
authors: Huang
mesh_terms: D000072283:A549 Cells; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D054648:Protein Phosphatase 2 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000071636:Protein Phosphatase 2C / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits / Q000235:genetics; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2 / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; C000627071:PABIR1 protein, human; D010750:Phosphoproteins; D021122:Protein Subunits; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2
keywords: FAM122A; PP2A; cell growth; phosphatase activity; ubiquitination