Multiple Types of Guanine Nucleotide Exchange Factors (GEFs) for Rab Small GTPases

Cell Struct Funct. 2016 Jul 9;41(2):61-79. doi: 10.1247/csf.16008. Epub 2016 May 27.


Rab small GTPases are highly conserved master regulators of membrane traffic in all eukaryotes. The same as the activation and inactivation of other small GTPases, the activation and inactivation of Rabs are tightly controlled by specific GEFs (guanine nucleotide exchange factors) and GAPs (GTPase-activating proteins), respectively. Although almost all Rab-GAPs reported thus far have a TBC (Tre-2/Bub2/Cdc16)/Rab-GAP domain in common, recent accumulating evidence has indicated the existence of a number of structurally unrelated types of Rab-GEFs, including DENN proteins, VPS9 proteins, Sec2 proteins, TRAPP complexes, heterodimer GEFs (Mon1-Ccz1, HPS1-HPS4 (BLOC-3 complex), Ric1-Rgp1 and Rab3GAP1/2), and other GEFs (e.g., REI-1 and RPGR). In this review article we provide an up-to-date overview of the structures and functions of all putative Rab-GEFs in mammals, with a special focus on their substrate Rabs, interacting proteins, associations with genetic diseases, and intracellular localizations.

Publication types

  • Review

MeSH terms

  • Animals
  • Guanine Nucleotide Exchange Factors / chemistry
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Guanosine Diphosphate / metabolism
  • Guanosine Triphosphate / metabolism
  • Humans
  • Protein Transport
  • rab GTP-Binding Proteins / metabolism*


  • Guanine Nucleotide Exchange Factors
  • Guanosine Diphosphate
  • Guanosine Triphosphate
  • rab GTP-Binding Proteins