QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 16, Issue 12, 5699-5709, December 2005

This Article Full Text Full Text (PDF) Supplemental Material All Versions of this Article: E05-03-0204v1 16/12/5699    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Strick, D. J. Articles by Elferink, L. A. Search for Related Content PubMed PubMed Citation Articles by Strick, D. J. Articles by Elferink, L. A.

Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment

David J. Strick ^*, and Lisa A. Elferink ^* 

^* Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-1043; Sealy Center for Cancer Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-1043

Submitted March 11, 2005; Revised September 7, 2005; Accepted September 16, 2005
Monitoring Editor: Suzanne Pfeffer

Sorting endosomes and the endocytic recycling compartment are critical intracellular stores for the rapid recycling of internalized membrane receptors to the cell surface in multiple cell types. However, the molecular mechanisms distinguishing fast receptor recycling from sorting endosomes and slow receptor recycling from the endocytic recycling compartment remain poorly understood. We previously reported that Rab15 differentially regulates transferrin receptor trafficking through sorting endosomes and the endocytic recycling compartment, suggesting a role for distinct Rab15-effector interactions at these endocytic compartments. In this study, we identified the novel protein Rab15 effector protein (REP15) as a binding partner for Rab15-GTP. REP15 is compartment specific, colocalizing with Rab15 and Rab11 on the endocytic recycling compartment but not with Rab15, Rab4, or early endosome antigen 1 on sorting endosomes. REP15 interacts directly with Rab15-GTP but not with Rab5 or Rab11. Consistent with its localization, REP15 overexpression and small interfering RNA-mediated depletion inhibited transferrin receptor recycling from the endocytic recycling compartment, without affecting receptor entry into or recycling from sorting endosomes. Our data identify REP15 as a compartment-specific protein for receptor recycling from the endocytic recycling compartment, highlighting that the rapid and slow modes of transferrin receptor recycling are mechanistically distinct pathways.

Abbreviations used: Alexa-Tfn, Alexa⁵⁹⁴-labeled transferrin; B-Tfn, biotinylated transferrin; EEA1, early endosome antigen 1; ERC, endocytic recycling compartment; Mss4, mammalian suppressor of Sec4; REP15, Rab15 effector protein 15; SE, sorting endosome; Tfn, transferrin; TfR, transferrin receptor.

The online version of this article contains supplemental material at MBC Online (http://www.molbiolcell.org).

Address correspondence to: Lisa A. Elferink (laelferi{at}utmb.edu).

This article has been cited by other articles:

				D. M. Henderson and S. D. Conner A Novel AAK1 Splice Variant Functions at Multiple Steps of the Endocytic Pathway Mol. Biol. Cell, July 1, 2007; 18(7): 2698 - 2706. [Abstract] [Full Text] [PDF]