Gene Symbol: Igbp1
Description: immunoglobulin (CD79A) binding protein 1
Alias: AI115586, AI662457, AW208785, C81413, Pc52, Tap42, p52, immunoglobulin-binding protein 1, CD79a-binding protein 1, alpha 4, alpha4 phosphoprotein, lymphocyte signal transduction molecule alpha 4, phosphoprotein, component, 52 kDa, protein phosphatase 2/4/6 regulatory subunit
Species: mouse
Products:     Igbp1

Top Publications

  1. Onda M, Inui S, Maeda K, Suzuki M, Takahashi E, Sakaguchi N. Expression and chromosomal localization of the human alpha 4/IGBP1 gene, the structure of which is closely related to the yeast TAP42 protein of the rapamycin-sensitive signal transduction pathway. Genomics. 1997;46:373-8 pubmed
    To study the function of the B cell signal transduction molecule alpha 4 (IGBP1), we isolated a human alpha 4 (IGBP1) gene that has sequence similarity to the yeast protein (TAP42) involved in the rapamycin-sensitive signal transduction ..
  2. Liu J, Prickett T, Elliott E, Meroni G, Brautigan D. Phosphorylation and microtubule association of the Opitz syndrome protein mid-1 is regulated by protein phosphatase 2A via binding to the regulatory subunit alpha 4. Proc Natl Acad Sci U S A. 2001;98:6650-5 pubmed
    ..Human birth defects may result from environmental or genetic disruption of this regulatory cycle. ..
  3. LeNoue Newton M, Watkins G, Zou P, Germane K, McCorvey L, Wadzinski B, et al. The E3 ubiquitin ligase- and protein phosphatase 2A (PP2A)-binding domains of the Alpha4 protein are both required for Alpha4 to inhibit PP2A degradation. J Biol Chem. 2011;286:17665-71 pubmed publisher
    ..Structurally, Alpha4 differs from its yeast homolog, Tap42, in two important ways: 1) the position of the helix containing the PP2Ac-binding residues is in a more open ..
  4. Kong M, Ditsworth D, Lindsten T, Thompson C. Alpha4 is an essential regulator of PP2A phosphatase activity. Mol Cell. 2009;36:51-60 pubmed publisher
    ..These findings demonstrate that alpha4 plays a required role in regulating the assembly and maintenance of adaptive PP2A phosphatase complexes. ..
  5. Eleftheriadou O, Boguslavskyi A, Longman M, Cowan J, Francois A, Heads R, et al. Expression and regulation of type 2A protein phosphatases and alpha4 signalling in cardiac health and hypertrophy. Basic Res Cardiol. 2017;112:37 pubmed publisher
    ..This study illustrates the significance and altered activity of the type 2A protein phosphatase-alpha4 complex in healthy and hypertrophied myocardium. ..
  6. Maeda K, Inui S, Sanjo H, Sakaguchi N. The gene structure and promoter analysis of mouse lymphocyte signal transduction molecule alpha 4 that is related to the yeast TAP42 involved in a rapamycin-sensitive pathway. Gene. 1998;210:287-95 pubmed
    The mouse alpha 4 phosphoprotein encoding a component associated with the B cell antigen receptor (BCR)-mediated signal transduction is suggested to be involved in a unique rapamycin-sensitive pathway...
  7. Nanahoshi M, Nishiuma T, Tsujishita Y, Hara K, Inui S, Sakaguchi N, et al. Regulation of protein phosphatase 2A catalytic activity by alpha4 protein and its yeast homolog Tap42. Biochem Biophys Res Commun. 1998;251:520-6 pubmed
    Recent studies have revealed that the alpha4 protein, a mammalian homolog of yeast Tap42, is associated with the protein phosphatase 2A catalytic subunit (PP2A-C), however, effects of the association of alpha4 with PP2A-C on its ..
  8. Maeda K, Inui S, Tanaka H, Sakaguchi N. A new member of the alpha4-related molecule (alpha4-b) that binds to the protein phosphatase 2A is expressed selectively in the brain and testis. Eur J Biochem. 1999;264:702-6 pubmed
    ..The alpha4-b protein associates with the catalytic subunit of PP2A (PP2Ac), suggesting that the alpha4-b protein is involved in the regulation of phosphatase activity in neuronal cells. ..
  9. Prickett T, Brautigan D. The alpha4 regulatory subunit exerts opposing allosteric effects on protein phosphatases PP6 and PP2A. J Biol Chem. 2006;281:30503-11 pubmed
    ..These catalytic subunits associate with a common subunit called alpha4 (related to yeast Tap42). Here, we characterized recombinant PP6 and PP2A catalytic monomers and alpha4.phosphatase heterodimers...

More Information


  1. Hua D, Inui S, Yamashita T, Maeda K, Takagi K, Takeda J, et al. T cell-specific gene targeting reveals that alpha4 is required for early T cell development. Eur J Immunol. 2003;33:1899-906 pubmed
    ..A severe impairment of CD3-induced expression of CD25 was also observed. These data suggest that alpha4 plays a critical role in the proliferation of thymocytes, which is necessary for early T cell development. ..
  2. Kong M, Fox C, Mu J, Solt L, Xu A, Cinalli R, et al. The PP2A-associated protein alpha4 is an essential inhibitor of apoptosis. Science. 2004;306:695-8 pubmed
    ..Thus, mammalian cell viability depends on repression of transcription-initiated apoptosis mediated by a component of PP2A. ..
  3. Kloeker S, Reed R, McConnell J, Chang D, Tran K, Westphal R, et al. Parallel purification of three catalytic subunits of the protein serine/threonine phosphatase 2A family (PP2A(C), PP4(C), and PP6(C)) and analysis of the interaction of PP2A(C) with alpha4 protein. Protein Expr Purif. 2003;31:19-33 pubmed
    ..Together, these findings increase our understanding of the biochemistry of alpha4/phosphatase complexes and suggest that the alpha4 binding site within PP2A may include the phosphatase catalytic domain. ..
  4. Everett A, Brautigan D. Developmental expression of alpha4 protein phosphatase regulatory subunit in tissues affected by Opitz syndrome. Dev Dyn. 2002;224:461-4 pubmed
    ..The alpha4 gene lies in the linkage interval for FG syndrome, characterized by skeletal muscle and brain defects that coincide closely to the expression pattern of alpha4. ..
  5. Prickett T, Brautigan D. Overlapping binding sites in protein phosphatase 2A for association with regulatory A and alpha-4 (mTap42) subunits. J Biol Chem. 2004;279:38912-20 pubmed
    ..a scaffold subunit (A subunit or PR65); however, PP2Ac alternatively binds to alpha-4, a subunit related to yeast Tap42 protein, which also associates with phosphatases PP4 or PP6...
  6. Inui S, Kuwahara K, Mizutani J, Maeda K, Kawai T, Nakayasu H, et al. Molecular cloning of a cDNA clone encoding a phosphoprotein component related to the Ig receptor-mediated signal transduction. J Immunol. 1995;154:2714-23 pubmed
    ..Here we isolated a cDNA clone (alpha 4) from a murine bone marrow cDNA library in lambda gt-11 vector by the 19-14 mAb...
  7. Yamashita T, Inui S, Maeda K, Hua D, Takagi K, Fukunaga K, et al. Regulation of CaMKII by alpha4/PP2Ac contributes to learning and memory. Brain Res. 2006;1082:1-10 pubmed
    ..These results suggest that alpha4 and PP2A may thus play an important role in CaMKIIalpha regulation and thereby also influence learning. ..
  8. Prickett T, Brautigan D. Cytokine activation of p38 mitogen-activated protein kinase and apoptosis is opposed by alpha-4 targeting of protein phosphatase 2A for site-specific dephosphorylation of MEK3. Mol Cell Biol. 2007;27:4217-27 pubmed
    ..The results show that alpha-4 targets PP2A activity to MEK3 to suppress p38 MAPK activation by cytokines, thereby inhibiting apoptosis and anoikis. ..
  9. Grech G, Blázquez Domingo M, Kolbus A, Bakker W, Mullner E, Beug H, et al. Igbp1 is part of a positive feedback loop in stem cell factor-dependent, selective mRNA translation initiation inhibiting erythroid differentiation. Blood. 2008;112:2750-60 pubmed publisher
    ..One of the targets, Immunoglobulin binding protein 1 (Igbp1), is a regulatory subunit of protein phosphatase 2A (Pp2a) sustaining mTOR signaling...
  10. Inui S, Maeda K, Hua D, Yamashita T, Yamamoto H, Miyamoto E, et al. BCR signal through alpha 4 is involved in S6 kinase activation and required for B cell maturation including isotype switching and V region somatic hypermutation. Int Immunol. 2002;14:177-87 pubmed
    b>alpha 4 potentially mediates BCR signals through a rapamycin-sensitive TOR pathway...
  11. Short K, Hopwood B, Yi Z, Cox T. MID1 and MID2 homo- and heterodimerise to tether the rapamycin-sensitive PP2A regulatory subunit, alpha 4, to microtubules: implications for the clinical variability of X-linked Opitz GBBB syndrome and other developmental disorders. BMC Cell Biol. 2002;3:1 pubmed
    ..Using this system we identified Alpha 4, a regulatory subunit of PP2-type phosphatases and a key component of the rapamycin-sensitive signaling pathway, ..
  12. Kuwahara K, Matsuo T, Nomura J, Igarashi H, Kimoto M, Inui S, et al. Identification of a 52-kDa molecule (p52) coprecipitated with the Ig receptor-related MB-1 protein that is inducibly phosphorylated by the stimulation with phorbol myristate acetate. J Immunol. 1994;152:2742-52 pubmed
    ..prepared by immunizing the 52-kDa protein purified from SDS-PAGE, could detect the similar 52-kDa phosphoprotein (p52) expressed on the cell surface...