Ras-related protein Rab-44 (RAB44)

Ras-related protein Rab-44 (RAB44) is a member of the Rab GTPase family, classified as a “large Rab GTPase” due to its additional EF-hand and coiled-coil domains beyond the classical Rab GTPase domain[2][3]. Like other Rab proteins, it functions as a molecular switch cycling between active (GTP-bound) and inactive (GDP-bound) states, thereby regulating vesicle trafficking and membrane dynamics. Rab44 is predominantly expressed in bone marrow and cells of the granulocyte and mast cell lineages, where it plays a key role in granule/lysosomal exocytosis and the release of mediators such as histamine[3][4][6]. Mouse studies show that Rab44 negatively regulates osteoclast differentiation (bone resorption) and is required for efficient IgE-mediated degranulation of mast cells, influencing in vivo anaphylactic responses[2][4][6]. It is predicted to be located in plasma and granule membranes and is involved in immune cell function, but there is currently no evidence that it is a direct therapeutic target, nor are there any approved drugs targeting it for disease treatment in humans[3][4][10].

Other names

RAB44RASD3RASL13dJ431A14.3member RAS oncogene family