RAB27A+RAB27B Recombinant Rabbit Monoclonal Antibody [PSH24-34] (HA724441)

UNIPROT #

P51159

PROTEIN NAME

RAB27A+RAB27B

SYNONYMS

Ras-related protein Rab-27A;EC:3.6.5.2;Rab-27;GTP-binding protein Ram;RAB27A;RAB27;Ras-related protein Rab-27B;C25KG;RAB27B

SUBCELLULAR LOCATION

Membrane, Melanosome, Late endosome, Lysosome.

FUNCTION

Rab27 is a member of the Rab subfamily of GTPases. Rab27 is post-translationally modified by the addition of two geranylgeranyl groups on the two C-terminal cysteines. Rab27 has two main isoforms: Rab27a and Rab27b. These are similar in primary composition, with 66% similarity between nucleotides. Most of their differences originate from their C-terminal, which is responsible for interactions with proteins such as SPIREs. Thus, these isoforms play different roles in the regulation pathway of exocytosis. Throughout the process of exocytosis, Rab27a and Rab27b are found in different sections of the cell, with Rab27b found commonly in the TGN and Rab27a usually bound to multivesicular endosomes with CD63 present. Rab27 plays a key role in the regulation of exocytosis of vesicles in various cellular organelles. In certain secretory organelles, such as Weibel-Palade bodies in endothelial cells, Rab27a is recruited during organelle maturation, rendering them from a secretion-incompetent to a secretion-comptetent state. Rab27 uses effectors to tether vesicles to the cytoskeleton and transport them to the plasma membrane, where they undergo fusion. They ensure that vesicles attach correctly, in the proper orientation, at the dedicated site of fusion. However, fusion itself is started when effectors bind SNARE proteins that catalyze the start of exocytosis.