RAB33B, Member RAS Oncogene Family (RAB33B)

Small GTP-binding proteins of the RAB family, such as RAB33B, play important roles at defined steps of vesicular transport in protein secretion and the endocytosis pathway.Zheng et al. (1998) cloned and characterized mouse Rab33b, a small GTP-binding protein closely related to RAB33A, especially in the GTP-binding domain. The Rab33b gene encodes a 229-amino acid protein. Unlike mouse and human RAB33A, which have tissue-specific expression, Northern blot analysis indicated that mouse Rab33b is ubiquitously expressed. Using immunofluorescence studies, Zheng et al. (1998) showed that Rab33b is localized to the medial Golgi cisternae, suggesting that it may play a role in intra-Golgi transport.