RAB27A, Member RAS Oncogene Family (RAB27A)

RAB27A belongs to the small GTPase superfamily, Rab family. The protein is membrane-bound and may be involved in protein transport and small GTPase mediated signal transduction. Mutations in this gene are associated with Griscelli syndrome type 2. Alternative splicing occurs at this locus and four transcript variants encoding the same protein have been identified. The predicted 221-amino acid RAB27A human protein shares 96% identity with rat Ram. Sequence comparisons revealed that RAB27A and RAB27B are 71% identical and comprise a Rab subfamily. Northern blot analysis indicated that RAB27A was expressed as 1.3-, 2.7-, and 3.7-kb mRNAs in most human tissues and cell lines examined. Recombinant RAB27A and RAB27B exhibited GTP-binding activity in vitro.