RAB27A : RAB27A, member RAS oncogene family
Description
The RAB27A (RAB27A, member RAS oncogene family) is a protein-coding gene located on chromosome 15.
The RAB27A gene provides instructions for making a protein that is involved in vesicle trafficking, which moves proteins and other molecules within cells in sac-like structures called vesicles. Although the Rab27a protein is found in cells and tissues throughout the body, it appears to be most critical in pigment-producing cells called melanocytes and in certain immune system cells. In melanocytes, the Rab27a protein helps transport structures called melanosomes. These structures produce a pigment called melanin, which is the substance that gives skin, hair, and eyes their color (pigmentation). Rab27a interacts with proteins produced from the MLPH and MYO5A genes to form a complex that transports melanosomes to the outer edges of melanocytes. From there, the melanosomes are transferred to other types of cells, where they provide the pigment needed for normal hair, skin, and eye coloring. The Rab27a protein also plays an important role in immune system cells called T-lymphocytes. These cells recognize and attack foreign invaders, such as viruses and bacteria, to prevent infection and illness. Specifically, Rab27a is involved in cytotoxic granule exocytosis, which is the process by which T-lymphocytes release cell-killing (cytotoxic) compounds to destroy foreign invaders.
RAB27A is a small GTPase that switches between an active GTP-bound state and an inactive GDP-bound state. When active, it binds to various effector proteins to regulate the late endocytic pathway, including the positioning, maturation, and secretion of endosomes. RAB27A plays a crucial role in cytotoxic granule exocytosis in lymphocytes, being essential for both granule maturation and docking/priming at the immunological synapse.
RAB27A is also known as GS2, HsT18676, RAB27, RAM.
