RAB7B, Member RAS Oncogene Family (RAB7B)

Rab7b, a novel lysosome-associated small GTPase, is involved in monocytic differentiation of human acute promyelocytic leukemia cells. Rab7b mRNA is expressed in human heart, placenta, lung, skeletal muscle, and peripheral blood leukocyte. In the peripheral blood, Rab7b is specifically detected in CD14(+) cells, but not in CD4(+), CD8(+), CD19(+) or CD56(+) cells. When immature DCs are matured with lipopolysaccharide (LPS), Rab7b expression is gradually downregulated, while Rab7b is upregulated when monocytes are activated by LPS treatments.Rab7b expression is upregulated after phorbol myristate acetate (PMA)-induced monocytic differentiation. Rab7b is a lysosome-localized monocytic cell-specific small GTPase, and is involved in PMA-induced APL cell differentiation and possibly in regulation of monocyte functions.