RAB4A, Member RAS Oncogene Family (RAB4A)

The mammalian RAB proteins show striking similarities to the S. cerevisiae YPT1 and SEC4 proteins, Ras-related GTP-binding proteins involved in the regulation of secretion. Zahraoui et al. (1989) isolated cDNAs encoding RAB4 and several other human RAB proteins. The predicted 213-amino acid human RAB4 protein shares 98% and 50% identity with rat Rab4 and human RAB2, respectively. Northern blot analysis revealed that the RAB4 gene was expressed weakly as 1.8-, 3.1-, and 3.6-kb mRNAs in a human fibroblast cell line. Barbosa et al. (1995) referred to this locus as RAV4A and mapped the mouse homolog by interspecific backcross analysis to the distal end of mouse chromosome 8. The authors mapped Rab4b to proximal mouse chromosome 7.