Q5R4G2 · PA1B2_PONAB

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).

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).

Catalytic activity

Activity regulation

Beta subunit (PAFAH1B1) stimulates the acetylhydrolase activity of the alpha2/alpha2 catalytic homodimer.

Features

Showing features for active site.

TypeIDPosition(s)Description
Active site48
Active site193
Active site196

GO annotations

AspectTerm
Cellular Component1-alkyl-2-acetylglycerophosphocholine esterase complex
Cellular Componentcytosol
Cellular Componentfibrillar center
Cellular Componentplasma membrane
Molecular Function1-alkyl-2-acetylglycerophosphocholine esterase activity
Molecular Functionplatelet-activating factor acetyltransferase activity
Molecular Functionprotein heterodimerization activity
Molecular Functionprotein homodimerization activity
Biological Processlipid catabolic process
Biological Processpositive regulation of macroautophagy
Biological Processspermatogenesis

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Platelet-activating factor acetylhydrolase IB subunit alpha2
  • EC number
  • Alternative names
    • PAF acetylhydrolase 30 kDa subunit (PAF-AH 30 kDa subunit)
    • PAF-AH subunit beta (PAFAH subunit beta)

Gene names

    • Name
      PAFAH1B2
    • Synonyms
      PAFAHB

Organism names

Accessions

  • Primary accession
    Q5R4G2

Proteomes

PTM/Processing

Features

Showing features for initiator methionine, modified residue, chain.

TypeIDPosition(s)Description
Initiator methionine1Removed
Modified residue2N-acetylserine
Modified residue2Phosphoserine
ChainPRO_00002526832-229Platelet-activating factor acetylhydrolase IB subunit alpha2
Modified residue64Phosphoserine
Modified residue220Phosphothreonine

Keywords

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).

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    229
  • Mass (Da)
    25,569
  • Last updated
    2004-12-21 v1
  • Checksum
    14CF5D48621AA504
MSQGDSNPAAIPHAAEDIQGDDRWMSQHNRFVLDCKDKEPDVLFVGDSMVQLMQQYEIWRELFSPLHALNFGIGGDTTRHVLWRLKNGELENIKPKVIVVWVGTNNHENTAEEVAGGIEAIVQLINTRQPQAKIIVLGLLPRGEKPNPLRQKNAKVNQLLKVSLPKLANVQLLDTDGGFVHSDGAISCHDMFDFLHLTGGGYAKICKPLHELIMQLLEETPEEKQTTIA

Computationally mapped potential isoform sequences

There are 3 potential isoforms mapped to this entry

View all
EntryEntry nameGene nameLength
A0A2J8X1B3A0A2J8X1B3_PONABPAFAH1B2132
A0A2J8X1C1A0A2J8X1C1_PONABPAFAH1B2203
A0A2J8X1D1A0A2J8X1D1_PONABPAFAH1B2156

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CR861287
EMBL· GenBank· DDBJ
CAH93354.1
EMBL· GenBank· DDBJ
mRNA

Genome annotation databases

Similar Proteins

Disclaimer

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