4ny3

Publication Abstract from PubMed

Abstract Protein phosphatase 2A (PP2A) is a highly abundant heterotrimeric Ser/Thr phosphatase involved in the regulation of a variety of signaling pathways. The PP2A phosphatase activator (PTPA) is an ATP-dependent activation chaperone, which plays a key role in the biogenesis of active PP2A. The C-terminal tail of the catalytic subunit of PP2A is highly conserved and can undergo a number of posttranslational modifications that serve to regulate the function of PP2A. Here we have studied structurally the interaction of PTPA with the conserved C-terminal tail of the catalytic subunit carrying different posttranslational modifications. We have identified an additional interaction site for the invariant C-terminal tail of the catalytic subunit on PTPA, which can be modulated via posttranslational modifications. We show that phosphorylation of Tyr307PP2A-C or carboxymethylation of Leu309PP2A-C abrogates or diminishes binding of the C-terminal tail, whereas phosphorylation of Thr304PP2A-C is of no consequence. We suggest that the invariant C-terminal residues of the catalytic subunit can act as affinity enhancer for different PP2A interaction partners, including PTPA, and a different 'code' of posttranslational modifications can favour interactions to one subunit over others.

Structural basis for PTPA interaction with the invariant C-terminal tail of PP2A.,Low C, Quistgaard EM, Kovermann M, Anandapadamanaban M, Balbach J, Nordlund P Biol Chem. 2014 Jul 1;395(7-8):881-9. doi: 10.1515/hsz-2014-0106. PMID:25003389^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.