transmembrane protein 55B (type 1 phosphatidylinositol 4,5-bisphosphate 4-phosphatase, Ptdins-4,5-P2 4-Ptase 1, TMEM55B C14orf9)

Function

• catalyzes the hydrolysis of the 4-position phosphate of phosphatidylinositol 4,5-bisphosphate
• does not hydrolyze phosphatidylinositol 3,4,5-trisphosphate, phosphatidylinositol 3,4-bisphosphate, inositol 3,5-bisphosphate, inositol 3,4-bisphosphate, phosphatidylinositol 5-monophosphate, phosphatidylinositol 4-monophosphate & phosphatidylinositol 3-monophosphate

 1-phosphatidyl-myo-inositol 4,5-bisphosphate + H2O
                     <-->
1-phosphatidyl-1D-myo-inositol 5-phosphate + phosphate

Compartment

late endosome membrane, lysosome membrane

Alternative splicing

named isoforms=3 Note=May be due to intron retention

Expression

ubiquitous

More general terms

• phosphomonoesterase
• membrane protein

Database

• UniProt: http://www.uniprot.org/uniprot/Q86T03.html