retina-specific copper amine oxidase; RAO; amine oxidase [copper-containing]; semicarbazide-sensitive amine oxidase; SSAO (AOC2)

Function

• modulates signal transmission in retina
• degrades biogenic amines dopamine, histamine, putrescine
• may play a role in adipogenesis
• topaquinone is generated by copper-dependent autoxidation of a specific Tyr
• forms heterodimer with AOC3, in vitro

RCH2NH2 + H2O + O2 <--> RCHO + NH2 + H2O2

Cofactor: binds 1 Cu+1/Cu+2 ion per subunit binds 2 Ca+2 per subunit contains 1 topaquinone per subunit

Kinetic parameters:

• KM=0.056 mM for tryptamine
• KM=0.077 mM for 2-phenylethylamine
• KM=0.167 mM for benzylamine
• KM=0.178 mM for p-tyramine
• KM=1.7 mM for methylamine

Structure

belongs to the copper/topaquinone oxidase family

Compartment

• isoform 1: cell membrane
• isoform 2: cytoplasm

Alternative splicing

• named isoforms=2
• additional isoforms seem to exist

Expression

• expressed in many tissues
• much higher expression in retina
• isoform 1 & isoform 2 are expressed in adipose tissue
  • up-regulated during in vitro adipocyte differentiation
• isoform 1 only seems to be expressed in thymus
• isoform 2 only expressed in testis

More general terms

• amine oxidoreductase
• Ca+2 binding protein
• glycoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=314
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:314
• OMIM: https://mirror.omim.org/entry/602268
• UniProt: http://www.uniprot.org/uniprot/O75106.html