Q5R4G2 · PA1B2_PONAB
- ProteinPlatelet-activating factor acetylhydrolase IB subunit alpha2
- GenePAFAH1B2
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids229 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score4/5
Function
function
Alpha2 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. The alpha2/alpha2 homodimer (PAFAH1B2/PAFAH1B2 homodimer) hydrolyzes PAF and 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylethanolamine (AAGPE) more efficiently than 1-O-alkyl-2-acetyl-sn-glycero-3-phosphoric acid (AAGPA). In contrast, the alpha1/alpha2 heterodimer(PAFAH1B3/PAFAH1B3 heterodimer) hydrolyzes AAGPA more efficiently than PAF, but has little hydrolytic activity towards AAGPE (By similarity).
May play a role in male germ cell meiosis during the late pachytenestage and meiotic divisions as well as early spermiogenesis (By similarity).
May play a role in male germ cell meiosis during the late pachytenestage and meiotic divisions as well as early spermiogenesis (By similarity).
Miscellaneous
Originally the subunits of the type I platelet-activating factor (PAF) acetylhydrolase was named alpha (PAFAH1B1), beta (PAFAH1B2) and gamma (PAFAH1B3) (By similarity).
Now these subunits have been renamed beta (PAFAH1B1), alpha2 (PAFAH1B2) and alpha1 (PAFAH1B3) respectively (By similarity).
Now these subunits have been renamed beta (PAFAH1B1), alpha2 (PAFAH1B2) and alpha1 (PAFAH1B3) respectively (By similarity).
Catalytic activity
- a 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine + H2O = 1-O-alkyl-sn-glycero-3-phosphocholine + acetate + H+This reaction proceeds in the forward direction.
- 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine + H2O = 1-O-hexadecyl-sn-glycero-3-phosphocholine + acetate + H+This reaction proceeds in the forward direction.
- 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphate + H2O = 1-O-hexadecyl-sn-glycero-3-phosphate + acetate + H+This reaction proceeds in the forward direction.
- 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphoethanolamine + H2O = 1-O-hexadecyl-sn-glycero-3-phosphoethanolamine + acetate + H+This reaction proceeds in the forward direction.
Activity regulation
Beta subunit (PAFAH1B1) stimulates the acetylhydrolase activity of the alpha2/alpha2 catalytic homodimer.
Features
Showing features for active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Active site | 48 | |||||
Sequence: S | ||||||
Active site | 193 | |||||
Sequence: D | ||||||
Active site | 196 | |||||
Sequence: H |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | 1-alkyl-2-acetylglycerophosphocholine esterase complex | |
Cellular Component | cytosol | |
Cellular Component | fibrillar center | |
Cellular Component | plasma membrane | |
Molecular Function | 1-alkyl-2-acetylglycerophosphocholine esterase activity | |
Molecular Function | platelet-activating factor acetyltransferase activity | |
Molecular Function | protein heterodimerization activity | |
Molecular Function | protein homodimerization activity | |
Biological Process | lipid catabolic process | |
Biological Process | positive regulation of macroautophagy | |
Biological Process | spermatogenesis |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended namePlatelet-activating factor acetylhydrolase IB subunit alpha2
- EC number
- Alternative names
Gene names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Pongo
Accessions
- Primary accessionQ5R4G2
Proteomes
Subcellular Location
PTM/Processing
Features
Showing features for initiator methionine, modified residue, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Modified residue | 2 | N-acetylserine | ||||
Sequence: S | ||||||
Modified residue | 2 | Phosphoserine | ||||
Sequence: S | ||||||
Chain | PRO_0000252683 | 2-229 | Platelet-activating factor acetylhydrolase IB subunit alpha2 | |||
Sequence: SQGDSNPAAIPHAAEDIQGDDRWMSQHNRFVLDCKDKEPDVLFVGDSMVQLMQQYEIWRELFSPLHALNFGIGGDTTRHVLWRLKNGELENIKPKVIVVWVGTNNHENTAEEVAGGIEAIVQLINTRQPQAKIIVLGLLPRGEKPNPLRQKNAKVNQLLKVSLPKLANVQLLDTDGGFVHSDGAISCHDMFDFLHLTGGGYAKICKPLHELIMQLLEETPEEKQTTIA | ||||||
Modified residue | 64 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 220 | Phosphothreonine | ||||
Sequence: T |
Keywords
- PTM
Interaction
Subunit
Forms a catalytic dimer which is either homodimer (alpha2/alpha2 homodimer) or heterodimer with PAFAH1B3 (alpha2/alpha1 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 (homodimer form) with PAFAH1B1 (homodimer form); PAFAH1B2 competes with NDEL1 for PAFAH1B1 binding (By similarity).
Interacts with VLDLR; this interaction may modulate the Reelin pathway (By similarity).
Interacts (homodimer form) with PAFAH1B1 (homodimer form); PAFAH1B2 competes with NDEL1 for PAFAH1B1 binding (By similarity).
Interacts with VLDLR; this interaction may modulate the Reelin pathway (By similarity).
Protein-protein interaction databases
Structure
Family & Domains
Sequence similarities
Belongs to the 'GDSL' lipolytic enzyme family. Platelet-activating factor acetylhydrolase IB beta/gamma subunits subfamily.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length229
- Mass (Da)25,569
- Last updated2004-12-21 v1
- Checksum14CF5D48621AA504
Computationally mapped potential isoform sequences
There are 3 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A2J8X1B3 | A0A2J8X1B3_PONAB | PAFAH1B2 | 132 | ||
A0A2J8X1C1 | A0A2J8X1C1_PONAB | PAFAH1B2 | 203 | ||
A0A2J8X1D1 | A0A2J8X1D1_PONAB | PAFAH1B2 | 156 |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CR861287 EMBL· GenBank· DDBJ | CAH93354.1 EMBL· GenBank· DDBJ | mRNA |