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Gene Review

Ppp1r13b  -  protein phosphatase 1, regulatory...

Mus musculus

Synonyms: AI449786, ASPP1, AW545810, Apoptosis-stimulating of p53 protein 1, Aspp1, ...
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High impact information on Ppp1r13b

  • Interestingly, this association occurred in the absence of ligand, and exposure of FDC-HER cells to EPO did not detectably affect levels of receptor-associated p85 or overall levels of p85 phosphorylation [1].
  • Coimmunoprecipitation of p85 with epitope-tagged EPO receptors was observed initially in FDC-HER cells labeled metabolically with [32P]orthophosphate, and association of these factors was confirmed by Western analyses of receptor immunoprecipitates using p85 antiserum [1].
  • Furthermore, recombinant p85 is modified in a similar manner when it is tyrosine phosphorylated in vitro by PDGF receptors [2].
  • Tyrosine phosphorylation of p85 does not block binding of the SH2-C domain and therefore does not release p85 from high-affinity binding sites on the receptor in vitro [2].
  • Although this interaction may activate phosphatidylinositol-kinase and is crucial for PDGF-induced mitogenesis, it has not been shown whether p85 is modified in the process. p85 contains two SH2 (Src homology) domains, designated SH2-N and SH2-C [2].

Biological context of Ppp1r13b

  • Among them, the ASPP family specifically regulate p53-dependent apoptosis [3].
  • Instead, phosphorylation may regulate the ability of the SH2-N of p85 to bind to a different portion of the PDGF receptor or to another molecule in the signaling complex [2].
  • Comparison of the ability of each receptor to couple with known second messengers revealed that both receptors associated with and/or tyrosine phosphorylated phospholipase C-gamma (PLC gamma) and phosphatidylinositol 3-kinase (p85) with similar stoichiometry [4].
  • Our data, therefore, point to the importance of subcellular localization of PI 3-kinase in signal transduction and to a novel action of p85 subunit-independent PI 3-kinase p110alpha in the stimulation by thrombin of p70(s6k) activation and actin stress fiber formation [5].
  • We have examined the role of phosphoinositide 3-kinases (PI3K) in interleukin (IL)-3-dependent cell cycle progression and compared the effects of LY294002 with expression of a dominant negative form of p85, termed Deltap85, which more specifically inhibits class I(A) PI3Ks [6].

Anatomical context of Ppp1r13b

  • The tumour-suppressor protein ASPP1 is nuclear in human germ cells and can modulate ratios of CD44 exon V5 spliced isoforms in vivo [7].
  • The SH2 domain-containing inositol 5'-phosphatase (SHIP) recruits the p85 subunit of phosphoinositide 3-kinase during FcgammaRIIb1-mediated inhibition of B cell receptor signaling [8].
  • By comparison, within 1 min after insulin stimulation, 40% of the total pool of the 85-kDa subunit of phosphatidylinositol 3-kinase (p85) is recruited from cytosol to IM, the greater part of which can be accounted for by binding to IRS-1 present in the IM [9].
  • Immunodepletion of p85 from cell lysates resulted in only partial depletion of p110alpha and p110alpha-associated PI 3-kinase activity, confirming the presence of a p85-free p110alpha pool located on the actin stress fibers [5].
  • Additionally, the increase in p85 association with the plasma-membrane lawns by PDGF remained intact following oxidation, whereas the insulin effect was decreased [10].

Associations of Ppp1r13b with chemical compounds

  • Studies with vanadate suggest that tyrosine phosphorylation of p85 is responsible for the modification of p85 detected by receptor blotting [2].
  • The first peak of VEGF expression was inhibited by LY294002, an inhibitor of phosphatidylinositol (PI) 3-kinase, and by the overexpression of dominant negative forms of p85 subunit of PI 3-kinase or Akt [11].
  • Interaction of the retinal insulin receptor beta-subunit with the p85 subunit of phosphoinositide 3-kinase [12].
  • In the present study a cell-permeable peptide that binds specifically to the SH2 domains of p85 has been evaluated for its ability to stimulate a mitogenic response in the C2 muscle cell line [13].
  • The abundance of the p85 regulatory subunit of PI3K and glucose transporter 4 was unaltered after CR [14].

Analytical, diagnostic and therapeutic context of Ppp1r13b

  • In this study, we have cloned the 41 kDa cytoplasmic region of the retinal insulin receptor (IRbeta) and used the two-hybrid assay of protein-protein interaction in the yeast Saccharomyces cerevisiae to demonstrate the interaction between the p85 subunit of PI3K and the cytoplasmic region of IRbeta [12].
  • We also used retinal organ cultures to demonstrate insulin activation of the insulin receptor and subsequent binding of p85, measured through GST pull-down assays with p85 fusion proteins [12].


  1. Association of the p85 regulatory subunit of phosphatidylinositol 3-kinase with an essential erythropoietin receptor subdomain. He, T.C., Zhuang, H., Jiang, N., Waterfield, M.D., Wojchowski, D.M. Blood (1993) [Pubmed]
  2. Modification of the 85-kilodalton subunit of phosphatidylinositol-3 kinase in platelet-derived growth factor-stimulated cells. Kavanaugh, W.M., Klippel, A., Escobedo, J.A., Williams, L.T. Mol. Cell. Biol. (1992) [Pubmed]
  3. ASPP2: a gene that controls life and death in vivo. Vives, V., Slee, E.A., Lu, X. Cell Cycle (2006) [Pubmed]
  4. Differences in substrate specificities of alpha and beta platelet-derived growth factor (PDGF) receptors. Correlation with their ability to mediate PDGF transforming functions. Heidaran, M.A., Beeler, J.F., Yu, J.C., Ishibashi, T., LaRochelle, W.J., Pierce, J.H., Aaronson, S.A. J. Biol. Chem. (1993) [Pubmed]
  5. A p85 subunit-independent p110alpha PI 3-kinase colocalizes with p70 S6 kinase on actin stress fibers and regulates thrombin-stimulated stress fiber formation in swiss 3T3 cells. Johanson, S.O., Naccache, P.A., Crouch, M.F. Exp. Cell Res. (1999) [Pubmed]
  6. Phosphoinositide 3-kinases can act independently of p27Kip1 to regulate optimal IL-3-dependent cell cycle progression and proliferation. Fox, B.C., Crew, T.E., Welham, M.J. Cell. Signal. (2005) [Pubmed]
  7. The tumour-suppressor protein ASPP1 is nuclear in human germ cells and can modulate ratios of CD44 exon V5 spliced isoforms in vivo. Thornton, J.K., Dalgleish, C., Venables, J.P., Sergeant, K.A., Ehrmann, I.E., Lu, X., Saunders, P.T., Elliott, D.J. Oncogene (2006) [Pubmed]
  8. The SH2 domain-containing inositol 5'-phosphatase (SHIP) recruits the p85 subunit of phosphoinositide 3-kinase during FcgammaRIIb1-mediated inhibition of B cell receptor signaling. Gupta, N., Scharenberg, A.M., Fruman, D.A., Cantley, L.C., Kinet, J.P., Long, E.O. J. Biol. Chem. (1999) [Pubmed]
  9. Dynamics of insulin signaling in 3T3-L1 adipocytes. Differential compartmentalization and trafficking of insulin receptor substrate (IRS)-1 and IRS-2. Inoue, G., Cheatham, B., Emkey, R., Kahn, C.R. J. Biol. Chem. (1998) [Pubmed]
  10. Oxidative stress impairs insulin but not platelet-derived growth factor signalling in 3T3-L1 adipocytes. Tirosh, A., Rudich, A., Potashnik, R., Bashan, N. Biochem. J. (2001) [Pubmed]
  11. Characterization of multiple signaling pathways of insulin in the regulation of vascular endothelial growth factor expression in vascular cells and angiogenesis. Jiang, Z.Y., He, Z., King, B.L., Kuroki, T., Opland, D.M., Suzuma, K., Suzuma, I., Ueki, K., Kulkarni, R.N., Kahn, C.R., King, G.L. J. Biol. Chem. (2003) [Pubmed]
  12. Interaction of the retinal insulin receptor beta-subunit with the p85 subunit of phosphoinositide 3-kinase. Rajala, R.V., McClellan, M.E., Chan, M.D., Tsiokas, L., Anderson, R.E. Biochemistry (2004) [Pubmed]
  13. Stimulation of mitogenesis by a cell-permeable PI 3-kinase binding peptide. Derossi, D., Williams, E.J., Green, P.J., Dunican, D.J., Doherty, P. Biochem. Biophys. Res. Commun. (1998) [Pubmed]
  14. Effects of long-term caloric restriction on early steps of the insulin-signaling system in mouse skeletal muscle. Argentino, D.P., Dominici, F.P., Al-Regaiey, K., Bonkowski, M.S., Bartke, A., Turyn, D. J. Gerontol. A Biol. Sci. Med. Sci. (2005) [Pubmed]
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