A non-specific tyrosine phosphatase that dephosphorylates a diverse number of substrates under acidic conditions (pH 4-6) including alkyl, aryl, and acyl orthophosphate monoesters and phosphorylated proteins (PubMed:10506173, PubMed:15280042, PubMed:20498373, PubMed:9584846). Has lipid phosphatase activity and inactivates lysophosphatidic acid in seminal plasma (PubMed:10506173, PubMed:15280042). ; [Isoform 2]: Tyrosine phosphatase that acts as a tumor suppressor of prostate cancer through dephosphorylation of ERBB2 and deactivation of MAPK-mediated signaling (PubMed:20498373). In addition to its tyrosine phosphatase activity has ecto-5′-nucleotidase activity in dorsal root ganglion (DRG) neurons. Generates adenosine from AMP which acts as a pain suppressor (By similarity). ; [PAPf39]: (Microbial infection) Forms amyloid beta-sheet fibrils in semen. These fibrils, termed SEVI (semen-derived enhancer of viral infection) capture HIV virions, attach them to target cells and enhance infection (PubMed:18083097, PubMed:19451623, PubMed:19897482). SEVI amyloid fibrils are degraded by polyphenol epigallocatechin-3-gallate (EGCG), a constituent of green tea (PubMed:19451623). Target cell attachment and enhancement of HIV infection is inhibited by surfen (PubMed:19897482). Also similarly boosts XMRV (xenotropic murine leukemia virus-related virus) infection (PubMed:19403677).
