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Intermolecular interactions of the p85alpha regulatory subunit of phosphatidylinositol 3-kinase

Harpur, AG; Layton, MJ; Das, P; Bottomley, MJ; Panayotou, G; Driscoll, PC; Waterfield, MD; (1999) Intermolecular interactions of the p85alpha regulatory subunit of phosphatidylinositol 3-kinase. Journal of Biological Chemistry , 274 (18) 12323 - 12332. Gold open access

Abstract

The regulatory subunit of phosphatidylinositol 3-kinase, p85, contains a number of well defined domains involved in protein-protein interactions, including an SH3 domain and two SH2 domains. In order to investigate in detail the nature of the interactions of these domains with each other and with other binding partners, a series of deletion and point mutants was constructed, and their binding characteristics and apparent molecular masses under native conditions were analyzed. The SH3 domain and the first proline-rich motif bound each other, and variants of p85 containing the SH3 and BH domains and the first proline- rich motif were dimeric. Analysis of the apparent molecular mass of the deletion mutants indicated that each of these domains contributed residues to the dimerization interface, and competition experiments revealed that there were intermolecular SH3 domain-proline-rich motif interactions and BH-BH domain interactions mediating dimerization of p85alpha both in vitro and in vivo. Binding of SH2 domain ligands did not affect the dimeric state of p85alpha. Recently, roles for the p85 subunit have been postulated that do not involve the catalytic subunit, and if p85 exists on its own we propose that it would be dimeric

Type:Article
Title:Intermolecular interactions of the p85alpha regulatory subunit of phosphatidylinositol 3-kinase
Open access status:An open access publication
Additional information:UI - 99230245 LA - Eng RN - EC 2.7.1.137 (1-Phosphatidylinositol 3-Kinase) RN - 0 (Isoenzymes) RN - 0 (Phosphopeptides) RN - 0 (Recombinant Proteins) PT - JOURNAL ARTICLE DA - 19990603 IS -0021-9258 SB - M SB - X CY - UNITED STATES JC - HIV AA - Author EM - 199908
Keywords:Phosphatidylinositols, 1-Phosphatidylinositol 3-Kinase, Isoenzymes, Phosphopeptides, recombinant, Recombinant Proteins, Proteins, United States, Hiv, 1 Phosphatidylinositol 3 Kinase, Amino Acid Sequence, analysis, cancer, Dimerization, In Vitro, ligands, metabolism, Molecular Sequence Data, p85, Proline, Protein Binding, src Homology Domains, Support, Non-U.S.Gov't, ANS, Nature, DIDS
UCL classification:UCL > School of Life and Medical Sciences > Faculty of Life Sciences > Biosciences (Division of)

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