Rab27arelated

Rab27a is a small GTPase that plays a crucial role in intracellular vesicle trafficking, particularly in the regulated secretion of various cellular products. It is a member of the Rab family of proteins, which are known for their involvement in vesicle budding, movement, and fusion. Rab27a is specifically associated with the transport and docking of secretory vesicles to the plasma membrane.

This protein functions by interacting with a range of effector proteins, which in turn recruit other machinery necessary for vesicle targeting and fusion. One of its well-characterized effectors is melanophilin (Mlph), which links Rab27a-bound vesicles to the actin cytoskeleton via myosin Va. This interaction is essential for the directed movement of vesicles to specific cellular locations. Rab27a is also involved in the release of neurotransmitters from synaptic vesicles and the secretion of cytokines from immune cells.

Mutations or deficiencies in Rab27a are linked to several human diseases. Griscelli syndrome type 2 (GS2) is an autosomal recessive disorder characterized by partial albinism, severe neurological impairment, and immunodeficiency. This condition arises from mutations in the RAB27A gene, leading to a failure in melanosome transport and cytotoxic T lymphocyte granule exocytosis. Research into Rab27a and its associated proteins continues to shed light on fundamental processes of cellular secretion and the molecular basis of related disorders.