Preferred Label : Rab GTPases in Endocytosis Pathway;
NCIt related terms : Rab GTPases Mark Targets in the Endocytotic Machinery;
Alternative definition : BIOCARTA: The eukaryotic cell contains compartments with distinct functions bounded
by lipid bilayer membranes. The movement of membrane vesicles between these compartments
allows proteins in the secretory pathway to move outward from the endoplasmic reticulum
(ER) to the Golgi, trans Golgi network (TGN), secretory vesicles, and the plasma membrane
and to be secreted into the extracellular environment. The trafficking of membrane
vesicles is also essential for endocytosis and the movement of material from the extracellular
environment into the early endosome (EE), late endosome (LE), and lysosome. The movement
of vesicles and their contents between these compartments, and their secretion, are
essential for a host of cellular functions, including the release of neurotransmitters
and hormones. The movement of membrane vesicles between all of these compartments
is regulated by members of the Rab family of GTPases, part of the ras superfamily
of genes, regulated through binding of GTP and hydrolysis of bound GTP to GDP. At
least eleven yeast genes in this family have been identified as Ypts, yeast transport
proteins, and over sixty mammalian Rab genes have been identified in this highly conserved
gene family. The products of the Rab genes regulate specific steps in vesicle transport.
Rab1 is involved in the movement of membranes from the ER through the Golgi. Rab3
regulates secretory vesicle release and Rab27 is also involved in regulated release
of secreted proteins. Rab5, 7 and 9 contribute to endocytosis while Rab4 and Rab11
mediate recycling from the endosome back to the plasma membrane. Rab11 is involved
in both endocytosis and exocytosis. As with other Ras family GTPases, the activity
of Rabs is regulated by guanine-nucleotide exchange factors (GEFs) and GAPs (GTPase
activating proteins). Downstream effectors must also interact with Rabs to transmit
their signals regulating each step of the membrane trafficking pathways including
vesicle formation, movement of vesicles between compartments, vesicle docking, fusion,
and membrane remodeling. Downstream effectors of the Rabs include Rabphilin-3 (vesicle
movement effector for Rab3), Rabphilin-11 (vesicle formation effector for Rab11),
and EEA1 (vesicle fusion and membrane remodeling). If Rabs are involved in more than
one role and other components of Rab signaling also interact with more than one Rab
this will further increase the complexity of the system. Elucidating the interaction
of Rabs and regulation of vesicle trafficking by other signaling pathways will be
a key area of research in the future. (This definition may be outdated - see the DesignNote.);
NCIt note : The BIOCARTA Definition (ALT_DEFINITION) for this pathway concept was provided by
BioCarta. This property was not created by, nor is it maintained by the NCI Thesaurus
staff. Additionally, BioCarta is no longer updating its pathway data; thus, the BIOCARTA
Definition might be outdated or inaccurate. Please see the Terms and Conditions for
Use at http://www.biocarta.com/.;
Biocarta ID : h_rabPathway;
Origin ID : C39207;
UMLS CUI : C1514676;
Semantic type(s)
- has_gene_product_element
- pathway_has_gene_element
