This web page was produced as an assignment for Gen677 at UW-Madison Spring 2009
Phenotypes Ontology
In AmiGO, SRD5A2 is known by the symbol P31213. A search of this gene reveals 11 different GO terms. Three of these terms are under cellular component, seven were under biological processes, and one was under molecular function. The diagram shown below shows the connection between the four main associations.
GO:0008209:Androgen metabolic processes
GO:0007267:Cell to Cell signaling
GO:0008584:Male Gonad Development
GO:0009917:Sterol 5-alpha reductase activity
The main clusters of the diagram stem from the male gonad development and the androgen metabolic processes categories. These are both important terms for this gene becuase of its involvement in balding via the conversion of testosterone to DHT (androgen metabolism), and also its role in another major disease, male pseudohermaphroditism (1). Further dissecting the four main associations can uncover the direct role this enzyme plays and how it can carry that out.
The cellular component diagram at right demonstrates the enzymes location in the cellular membrane. It was predicted earlier that this membrane has several transmembrane domains (TMHMM) and this is supported by gene ontology.
One association is steroid 5-alpha reductase activity, which is the process that SRD5A2 utilizes to reduce a functional group on testosterone (a steroid) into DHT. As one can see from the diagram on the Protein data page, the enzyme specifically reduces a CH-CH double bond in the process. You can see on the diagram at left that this is in fact the second GO term.
References
1. Andersson S, Berman DM, Jenkins EP, Russell DW (1991). "Deletion of steroid 5 alpha-reductase 2 gene in male pseudohermaphroditism.". Nature 354 (6349): 159–61. doi:10.1038/354159a0
2. The Gene Ontology:AmiGO
