phosphotidylinositol phosphatase PTPRQ (receptor-type tyrosine-protein phosphatase Q, PTP-RQ, PTPRQ)

Function

• phosphatidylinositol phosphatase
• required for auditory function
• may act by regulating the level of PtdIns(4,5)P2 (PIP2) level in the basal region of hair bundles
• can dephosphorylate a broad range of phosphatidylinositol phosphates, including PtdIns(3,4,5)P3 & most phosphatidylinositol monophosphates & diphosphates
• phosphate can be hydrolyzed from the D3 & D5 positions in the inositol ring
• has low tyrosine-protein phosphatase activity,however, the relevance of such activity in vivo is unclear

protein tyrosine phosphate + H2O <--> protein tyrosine + phosphate

Structure

• belongs to the protein-tyrosine phosphatase family receptor class 2A subfamily
• contains 18 fibronectin F3 modules
• contains 1 tyrosine-protein phosphatase domain

Compartment

membrane

Expression

• in developing kidney, localizes to basal membrane of podocytes, beginning when podocyte progenitors can first be identified in the embryonic kidney (at protein level)
• expressed in lung & kidney

More general terms

• glycoprotein
• membrane protein
• phosphomonoesterase

Database

• OMIM: https://mirror.omim.org/entry/603317
• UniProt: http://www.uniprot.org/uniprot/Q9UMZ3.html