Year: 2014
Type: article
Abstract: The lipid phosphatase activity of the tumor suppressor phosphatase and tensin homolog (PTEN) is enhanced by the presence of its biological product, phosphatidylinositol 4,5-bisphosphate (PI(4,5)P 2 ). This enhancement is suggested to occur via the product binding to the N-terminal region of the protein. PTEN effects on short-chain phosphoinositide 31 P linewidths and on the full field dependence of the spin-lattice relaxation rate (measured by high resolution field cycling 31 P NMR using spin-labeled protein) are combined with enzyme kinetics with the same short-chain phospholipids to characterize where PI(4,5)P 2 binds on the protein. The results are used to model a discrete site for a PI(4,5)P 2 molecule close to, but distinct from, the active site of PTEN. This PI(4,5)P 2 site uses Arg-47 and Lys-13 as phosphate ligands, explaining why PTEN R47G and K13E can no longer be activated by that phosphoinositide. Placing a PI(4,5)P 2 near the substrate site allows for proper orientation of the enzyme on interfaces and should facilitate processive catalysis.PTEN activity is enhanced by PI(4,5)P 2 via either an allosteric or interfacial effect. Results 31 P field cycling NMR with spin-labeled PTEN detects a PI(4,5)P 2 -binding site near but not in the active site. Conclusion A model for PTEN identifies Lys-13 and Arg-47 as part of the PI(4,5)P 2 site. Significance Occupation of the PI(4,5)P 2 -binding site on PTEN stabilizes productive interfacial binding.
Source: Journal of Biological Chemistry
Authors: Yang Wei, Boguslaw Stec, Alfred G. Redfield, Eranthie Weerapana, Mary F. Roberts
Institutions: Boston College, Brandeis University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
Funder: National Science Foundation
OpenAlex ID: W2010698590