FEATURES

FAMILY

DESCRIPTION

Also known as PA1B3_HUMAN, PAFAH1B3, PAFAHG. Alpha1 catalytic subunit of the cytosolic type I platelet-activating factor (PAF) acetylhydrolase (PAF-AH (I)) heterotetrameric enzyme that catalyzes the hydrolyze of the acetyl group at the sn-2 position of PAF and its analogs and modulates the action of PAF. The activity and substrate specificity of PAF-AH (I) are affected by its subunit composition. Both alpha1/alpha1 homodimer (PAFAH1B3/PAFAH1B3 homodimer) and alpha1/alpha2 heterodimer(PAFAH1B3/PAFAH1B2 heterodimer) hydrolyze 1-O-alkyl-2-acetyl-sn-glycero-3-phosphoric acid (AAGPA) more efficiently than PAF, but they have little hydrolytic activity towards 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylethanolamine (AAGPE). Plays an important role during the development of brain. Forms a catalytic dimer which is either homodimer (alpha1/alpha1 homodimer) or heterodimer with PAFAH1B2 (alpha1/alpha2 heterodimer). Component of the cytosolic (PAF-AH (I)) heterotetrameric enzyme, which is composed of PAFAH1B1 (beta), PAFAH1B2 (alpha2) and PAFAH1B3 (alpha1) subunits. The catalytic activity of the enzyme resides in the alpha1 (PAFAH1B3) and alpha2 (PAFAH1B2) subunits, whereas the beta subunit (PAFAH1B1) has regulatory activity. Trimer formation is not essential for the catalytic activity (By similarity). Interacts with VLDLR; this interaction may modulate the Reelin pathway (By similarity).

EXTERNAL LINKS

PAFAH1B3

Platelet-activating factor acetylhydrolase IB subunit alpha1

PAFAH1B3

Molecular Synopsis