This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Magadán, J. G.
Right arrow Articles by Mayorga, L. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Magadán, J. G.
Right arrow Articles by Mayorga, L. S.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, April 2006, p. 2595-2614, Vol. 26, No. 7
0270-7306/06/$08.00+0     doi:10.1128/MCB.26.7.2595-2614.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Rab22a Regulates the Sorting of Transferrin to Recycling Endosomes{ddagger}

Javier G. Magadán,1,2 M. Alejandro Barbieri,2,{dagger} Rosana Mesa,1 Philip D. Stahl,2 and Luis S. Mayorga1*

Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina,1 Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 631102

Received 8 August 2005/ Returned for modification 1 September 2005/ Accepted 13 January 2006

Rab22a is a member of the Rab family of small GTPases that localizes in the endocytic pathway. In CHO cells, expression of canine Rab22a (cRab22a) causes a dramatic enlargement of early endocytic compartments. We wondered whether transferrin recycling is altered in these cells. Expression of the wild-type protein and a GTP hydrolysis-deficient mutant led to the redistribution of transferrin receptor to large cRab22a-positive structures in the periphery of the cell and to a significant decrease in the plasma membrane receptor. Kinetic analysis of transferrin uptake indicates that internalization and early recycling were not affected by cRab22a expression. However, recycling from large cRab22a-positive compartments was strongly inhibited. A similar effect on transferrin transport was observed when human but not canine Rab22a was expressed in HeLa cells. After internalization for short periods of time (5 to 8 min) or at a reduced temperature (16°C), transferrin localized with endogenous Rab22a in small vesicles that did not tubulate with brefeldin A, suggesting that the endogenous protein is present in early/sorting endosomes. Rab22a depletion by small interfering RNA disorganized the perinuclear recycling center and strongly inhibited transferrin recycling. We speculate that Rab22a controls the transport of the transferrin receptor from sorting to recycling endosomes.

* Corresponding author. Mailing address: Instituto de Histología y Embriología (IHEM-CONICET), Casilla de Correo 56, 5500 Mendoza, Argentina. Phone: 54-261-4494143. Fax: 54-261-4494117. E-mail: lmayorga{at}fcm.uncu.edu.ar.

{ddagger} Supplemental material for this article may be found at http://mcb.asm.org/.

{dagger} Present address: Department of Biological Sciences, Florida International University, University Park, Miami, FL 33199.

Molecular and Cellular Biology, April 2006, p. 2595-2614, Vol. 26, No. 7
0022-538X/06/$08.00+0     doi:10.1128/MCB.26.7.2595-2614.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Zhu, H., Liang, Z., Li, G. (2009). Rabex-5 Is a Rab22 Effector and Mediates a Rab22-Rab5 Signaling Cascade in Endocytosis. Mol. Biol. Cell 20: 4720-4729 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»