RAB28, Member RAS Oncogene Family (RAB28)

RAS-related GTPases, such as RAB28, are GTP-dependent switches that operate signaling pathways in cell growth, metabolism, and organelle trafficking. RAB28S encodes a deduced 221-amino acid protein with domain characteristics of a GTPase, 9 potential phosphorylation sites, and a C-terminal farnesylation motif. RAB28L encodes a 220-amino acid protein that also has GTPase motifs and differs from RAB28S only at the C terminus, although it also has a C-terminal farnesylation motif. RAB28 is only distantly related to other RAB family members, sharing 31 to 33% amino acid identity with RAB1, RAB6 , RAB11, and RAB13. Northern blot analysis of human tissues detected weak expression of a 2.0-kb transcript only in testis. PCR analysis detected RAB28S in all tissues examined and RAB28L predominantly in testis