The Rab11-FIP1/RCP gene codes for multiple protein transcripts related to the plasma membrane recycling system.
Rab11a is a member of the Rab11 small GTPase family, and plays an important role in plasma membrane recycling. Rab11-Family Interacting Protein 1 (Rab11-FIP1) binds to Rab11 through a carboxyl-terminal amphipathic alpha helix. We have identified eight alternatively spliced Rab11-FIP1 gene transcripts from human chromosome 8. Among them, Rab11-FIP1A-D have carboxyl terminal Rab11 binding domains, while Rab11-FIP1E-H do not contain the Rab11 binding domain. While Rab11-FIP1B and F gene transcripts are ubiquitous, other Rab11-FIP1 transcripts demonstrate more limited patterns of expression in human tissue cDNAs. EGFP-Rab11-FIP1A-D proteins over-expressed in HeLa cells targeted to Rab11a-containing membranes, while EGFP-Rab11-FIP1E/F and H proteins did not localize with recycling system membranes. However, transferrin trafficking was not significantly altered in HeLa cells over-expressing expressing any of the EGFP-Rab11-FIP1 proteins. Rabbit polyclonal antibodies specific for Rab11-FIP1B and Rab11-FIP1C/RCP demonstrated that Rab11-FIP1B and Rab11-FIP1C/RCP are expressed endogenously. Strikingly, endogenous staining for Rab11-FIP1C/RCP only partially co-localized with EGFP-Rab11-FIP1A, EGFP-Rab11-FIP1B, and EGFP-Rab11a in the perinuclear region, indicating that Rab11-FIP1C/RCP resides in a differentiable subcellular compartment within the plasma membrane recycling system compared with Rab11-FIP1A and Rab11-FIP1B. These data suggest that Rab11-FIP1 proteins may play coordinated roles in regulating plasma membrane recycling with regional specificity within the Rab11a-containing recycling system.
Jin
Min
M
Department of Surgery, Vanderbilt University School of Medicine, Vanderbilt-Ingram Cancer Center and the Nashville VA Medical Center, Nashville, TN 37232, USA.
Goldenring
James R
JR
D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011247:Pregnancy; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014162:Transfection; D014168:Transferrin / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018076:DNA, Complementary; D008565:Membrane Proteins; C488966:RAB11FIP1 protein, human; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014168:Transferrin; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins