How do I cite GO?
The GO database and vocabularies are in the public domain. The annotations provided by member organizations in the Current Annotations table are also in the public domain. There are no restrictions on their use, although third parties are asked to give appropriate acknowledgement to the GO Consortium and to the appropriate member organization(s). To reference the Gene Ontology Consortium, please cite this paper:
Gene Ontology: tool for the unification of biology. The Gene Ontology Consortium (2000) Nature Genet. 25: 25-29 PDF
We also recommend that you include the date you scanned the GO information within your paper. The GO ontology, gene_associations, and documentation files have version numbers and dates, which may be used for this purpose. The GO is evolving and changes will occur with time.