PTEN, active
MerckPTEN hydrolyzes phosphate at the 3 position on the inositol ring of PtdIns(3,4,5)P3, and Ins(1,3,4,5)P4. Although PTEN has the consensus sequence of a protein tyrosine phosphatase, it dephosphorylates p-nitrophenylphosphate and other synthetic and protein substrates poorly. The greatest catalytic activity has been observed with the highly negatively charged, multiply phosphorylated polymer of (Glu-Tyr)n.