Biopolym. Cell. 2007; 23(4):318-323.
http://dx.doi.org/10.7124/bc.00076F
Structure and Function of Biopolymers
Interaction of serine/threonine protein phosphatase 5 with the protein products of tumour suppressor gene Tsc2
1, 2Malanchuk O. M., 1Palchevskyy S. S., 2Pozur V. K., 1, 3Gout I. T., 1Filonenko V. V.
  1. Institute of Molecular Biology and Genetics, NAS of Ukraine
    150, Akademika Zabolotnoho Str., Kyiv, Ukraine, 03680
  2. Taras Shevchenko National University of Kyiv
    64, Volodymyrska Str., Kyiv, Ukraine, 01033
  3. University College London
    Gower Str., London WC1E 6BT, UK

Abstract

Tuberous sclerosis (TSC) is a tumour disease caused by mutations in Tsc1 or Tsc2 genes. Both protein products of Tsc1 and Tsc2 form an intracellular complex possessing GTPase-activating (GAP) activity towards a small GTP binding protein Rheb. The activity of TSC1/2 complex is regulated by multiple phosphorylations of TSC2 mediated by several kinases, such as PKB/Akt, AMP-activated kinase (AMPK), ERK, MK2 and RSK1. So far, very little is known about the molecular mechanisms of TSC2 dephosphorylation. In the yeast two-hybrid screening, we have identified a number of potential TSC2 binding partners including protein phosphatase 5 (PP5). In this study, we provide the evidence that the interaction between TSC2 and PP5 also occurs in mammalian cells. Using TSC2+/+, p53–/– mouse embryo fibroblasts (MEFs) transiently overexpressing myc-PP5, we showed in the immunoprecipitation assay that TSC2 specifically associates with myc-PP5 in exponentially growing cells. The physiological relevance of identified interaction, especially the involvement of PP5 in the dephosphorylation of major regulatory sites is currently under investigation.
Keywords: TSC2, tuberous sclerosis, PP5, protein-protein interactions
Full text: (PDF, in English)

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