RAB1B Human

RAB1B belongs to the RAB protein family, which consists of low molecular mass monomeric GTPases. These proteins are localized on the cytoplasmic surfaces of distinct membrane-bound organelles. RAB1B cycles between an inactive GDP-bound form and an active GTP-bound form. The active form recruits various downstream effectors responsible for vesicle formation, movement, tethering, and fusion .

RAB1B plays a significant role in the early secretory pathway and is essential for vesicular transport between the ER and Golgi compartments. It is also involved in the initial events of autophagic vacuole development, which occur at specialized regions of the ER .

Mutations or dysregulation of RAB1B have been associated with several diseases. For instance, RAB1B has been linked to atrial septal defect 8 and immunodeficiency 73C with defective neutrophil chemotaxis and hypogammaglobulinemia . Additionally, RAB1B has been found to be significantly down-regulated in highly metastatic breast cancer cells. The down-regulation of RAB1B promotes the proliferation and migration of triple-negative breast cancer (TNBC) cells both in vitro and in vivo .

Mechanistically, the loss of RAB1B results in elevated expression of TGF-beta receptor 1 (TbetaR1) through decreased degradation of ubiquitin. This leads to increased levels of phosphorylated SMAD3 and TGF-beta-induced epithelial-mesenchymal transition (EMT). Consequently, low RAB1B expression correlates with poor prognosis in breast cancer patients .

Recombinant human RAB1B protein is often used in research to study its function and role in various cellular processes. The recombinant protein is typically expressed in HEK293 cells and purified to high levels of purity. It is used in various assays to investigate the biological activity and stability of RAB1B .