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Identification of a protein‐tyrosine phosphatase (SHP1) different from that associated with acid phosphatase in rat prostate
Author(s) -
Valencia Ana-Montserrat,
Oliva Jose L,
Bodega Guillermo,
Chiloeches Antonio,
López-Ruiz Pilar,
Prieto Juan C,
Susini Christiane,
Colás Begoña
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00235-4
Subject(s) - protein tyrosine phosphatase , phosphatase , acid phosphatase , concanavalin a , prostatic acid phosphatase , biochemistry , tyrosine , lectin , enzyme , prostate , dusp6 , protein phosphatase 2 , chemistry , microbiology and biotechnology , biology , in vitro , cancer , genetics
Using [ 32 P]poly(Glu,Tyr) as substrate, we have identified, for the first time, in the rat prostatic gland a protein‐tyrosine phosphatase activity different from that associated with prostatic acid phosphatase. Concanavalin A‐Sepharose 4B was used to separate the two protein‐tyrosyl phosphatases activities. The activity retained by the lectin had characteristics of the prostatic acid phosphatase. It was sensitive to inhibition by PNPP and the optimum pH shifted towards physiological values when [ 32 P]poly(Glu,Tyr) was used as substrate. However, the major protein‐tyrosine phosphatase activity was not retained by the lectin, and corresponded, at least in part, to SHP1 as probed by the presence of the protein, its mRNA and the loss of PTPase activity after immunodepletion of SHP1. This enzyme is localized within the epithelial cells. Thus, the coexistence of two protein‐tyrosine phosphatase activities in rat prostate, one associated with the acid phosphatase and the other related to SHP1, makes it necessary to analyze the importance of both activities in vivo and their possible function regarding prostatic cell growth and its regulation.