Related Experiment Video
Updated: Jul 2, 2026

Investigating Mast Cell Secretory Granules; from Biosynthesis to Exocytosis
Published on: January 26, 2015
Regulation of secretory vesicle traffic by Rab small GTPases
1Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan. nori@mail.tains.tohoku.ac.jp
Abstract:
Secretion is a fundamental biological activity of all eukaryotic cells by which they release certain substances in the extracellular space. It is considered a specialized mode of membrane trafficking that is achieved by docking and fusion of secretory vesicles to the plasma membrane (i.e., exocytosis). Secretory vesicle traffic is thought to be regulated by a family of Rab small GTPases, which are regulators of membrane traffic that are common to all eukaryotic cells. Classically, mammalian Rab3 subfamily members were thought to be critical regulators of secretory vesicle exocytosis in neurons and endocrine cells, but recent genetic and proteomic studies indicate that Rab3 is not the sole Rab isoform that regulates secretory vesicle traffic. Rather, additional Rab isoforms, especially Rab27 subfamily members, are required for this process. In this article I review the current literature on the function of Rab isoforms and their effectors in regulated secretory vesicle traffic.
More Related Videos
Related Concept Videos
Rab Cascades
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Coat Assembly and GTPases
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Pinching-off of Coated Vesicles

