| Structural highlights
Function
P85A_HUMAN Binds to activated (phosphorylated) protein-Tyr kinases, through its SH2 domain, and acts as an adapter, mediating the association of the p110 catalytic unit to the plasma membrane. Necessary for the insulin-stimulated increase in glucose uptake and glycogen synthesis in insulin-sensitive tissues. Plays an important role in signaling in response to FGFR1, FGFR2, FGFR3, FGFR4, KITLG/SCF, KIT, PDGFRA and PDGFRB. Likewise, plays a role in ITGB2 signaling.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The interaction of the Fyn SH3 domain with the p85 subunit of PI3-kinase is investigated using structural detail and thermodynamic data. The solution structure complex of the SH3 domain with a proline-rich peptide mimic of the binding site on the p85 subunit is described. This indicates that the peptide binds as a poly(L-proline) type II helix. Circular dichroism spectroscopic studies reveal that in the unbound state the peptide exhibits no structure. Thermodynamic data for the binding of this peptide to the SH3 domain suggest that the weak binding (approximately 31 microM) of this interaction is, in part, due to the entropically unfavorable effect of helix formation (delta S0 = -78 J.mol-1.K-1). Binding of the SH3 domain to the intact p85 subunit (minus its own SH3 domain) is tighter, and the entropic and enthalpic contributions are very different from those given by the peptide interaction (delta S0 = +252 J.mol-1.K-1; delta H0 = +44 kJ.mol-1). From these dramatically different thermodynamic measurements we are able to conclude that the interaction of the proline-rich peptide does not effectively mimic the interaction of the intact p85 subunit with the SH3 domain and suggest that other interactions could be important.
Structural and thermodynamic characterization of the interaction of the SH3 domain from Fyn with the proline-rich binding site on the p85 subunit of PI3-kinase.,Renzoni DA, Pugh DJ, Siligardi G, Das P, Morton CJ, Rossi C, Waterfield MD, Campbell ID, Ladbury JE Biochemistry. 1996 Dec 10;35(49):15646-53. PMID:8961927[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Vainikka S, Joukov V, Wennstrom S, Bergman M, Pelicci PG, Alitalo K. Signal transduction by fibroblast growth factor receptor-4 (FGFR-4). Comparison with FGFR-1. J Biol Chem. 1994 Jul 15;269(28):18320-6. PMID:7518429
- ↑ Miled N, Yan Y, Hon WC, Perisic O, Zvelebil M, Inbar Y, Schneidman-Duhovny D, Wolfson HJ, Backer JM, Williams RL. Mechanism of two classes of cancer mutations in the phosphoinositide 3-kinase catalytic subunit. Science. 2007 Jul 13;317(5835):239-42. PMID:17626883 doi:317/5835/239
- ↑ Mandelker D, Gabelli SB, Schmidt-Kittler O, Zhu J, Cheong I, Huang CH, Kinzler KW, Vogelstein B, Amzel LM. A frequent kinase domain mutation that changes the interaction between PI3Kalpha and the membrane. Proc Natl Acad Sci U S A. 2009 Oct 6;106(40):16996-7001. Epub 2009 Sep 23. PMID:19805105
- ↑ Renzoni DA, Pugh DJ, Siligardi G, Das P, Morton CJ, Rossi C, Waterfield MD, Campbell ID, Ladbury JE. Structural and thermodynamic characterization of the interaction of the SH3 domain from Fyn with the proline-rich binding site on the p85 subunit of PI3-kinase. Biochemistry. 1996 Dec 10;35(49):15646-53. PMID:8961927 doi:10.1021/bi9620969
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