Rab coupling protein (RCP), a novel Rab4 and Rab11 effector protein.
Rab4 and Rab11 are small GTPases belonging to the Ras superfamily. They both function as regulators along the receptor recycling pathway. We have identified a novel 80-kDa protein that interacts specifically with the GTP-bound conformation of Rab4, and subsequent work has shown that it also interacts strongly with Rab11. We name this protein Rab coupling protein (RCP). RCP is predominantly membrane-bound and is expressed in all cell lines and tissues tested. It colocalizes with early endosomal markers including Rab4 and Rab11 as well as with the transferrin receptor. Overexpression of the carboxyl-terminal region of RCP, which contains the Rab4- and Rab11-interacting domain, results in a dramatic tubulation of the transferrin compartment. Furthermore, expression of this mutant causes a significant reduction in endosomal recycling without affecting ligand uptake or degradation in quantitative assays. RCP is a homologue of Rip11 and therefore belongs to the recently described Rab11-FIP family.
Lindsay
Andrew J
AJ
Cell and Molecular Biology Laboratory, Department of Biochemistry, Lee Maltings, Prospect Row, University College Cork, Cork, Ireland.
Hendrick
Alan G
AG
Cantalupo
Giuseppina
G
Senic-Matuglia
Francesca
F
Goud
Bruno
B
Bucci
Cecilia
C
McCaffrey
Mary W
MW
D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000378:metabolism; D017353:Gene Deletion; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014168:Transferrin / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D020695:rab4 GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
D018076:DNA, Complementary; D020558:GTP Phosphohydrolases; D008024:Ligands; D011994:Recombinant Proteins; D014168:Transferrin; D020691:rab GTP-Binding Proteins; D020695:rab4 GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins