2ixm

Structural highlights

Function

[PTPA_HUMAN] PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Acts as a regulatory subunit for serine/threonine-protein phosphatase 2A (PP2A) modulating its activity or substrate specificity, probably by inducing a conformational change in the catalytic subunit, a proposed direct target of the PPIase. Can reactivate inactive phosphatase PP2A-phosphatase methylesterase complexes (PP2A(i)) in presence of ATP and Mg(2+) (By similarity). Reversibly stimulates the variable phosphotyrosyl phosphatase activity of PP2A core heterodimer PP2A(D) in presence of ATP and Mg(2+) (in vitro). The phosphotyrosyl phosphatase activity is dependent of an ATPase activity of the PP2A(D):PPP2R4 complex. Is involved in apoptosis; the function appears to be independent from PP2A.^{[1] [2]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

• Protein phosphatase
• Serine/threonine protein phosphatase

References

1. ↑ Azam S, Drobetsky E, Ramotar D. Overexpression of the cis/trans isomerase PTPA triggers caspase 3-dependent apoptosis. Apoptosis. 2007 Jul;12(7):1243-55. PMID:17333320 doi:http://dx.doi.org/10.1007/s10495-006-0050-8
2. ↑ Chao Y, Xing Y, Chen Y, Xu Y, Lin Z, Li Z, Jeffrey PD, Stock JB, Shi Y. Structure and mechanism of the phosphotyrosyl phosphatase activator. Mol Cell. 2006 Aug;23(4):535-46. PMID:16916641 doi:http://dx.doi.org/10.1016/j.molcel.2006.07.027
3. ↑ Leulliot N, Vicentini G, Jordens J, Quevillon-Cheruel S, Schiltz M, Barford D, van Tilbeurgh H, Goris J. Crystal structure of the PP2A phosphatase activator: implications for its PP2A-specific PPIase activity. Mol Cell. 2006 Aug 4;23(3):413-24. PMID:16885030 doi:10.1016/j.molcel.2006.07.008