JCB logo
amgmicro.com
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 1050K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wilson, J. M.
Right arrow Articles by Colton, T. L.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Wilson, J. M.
Right arrow Articles by Colton, T. L.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/1997//319 $5.00
The Journal of Cell Biology, Volume 136, Number 2, , 1997 319-330

Article

Targeting of an Intestinal Apical Endosomal Protein to Endosomes in Nonpolarized Cells



Jean M. Wilson and Tamara L. Colton

Department of Cell Biology and Anatomy and Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, Tucson, Arizona 85724

Polarized cells such as epithelial cells and neurons have distinct endosomal compartments associated with different plasma membrane domains. The endosomes of the neuronal cell body and the basolateral cytoplasm of epithelial cells are thought to perform cellular "housekeeping" functions such as the uptake of nutrients and metabolites, while the endosomes in the apical cytoplasm or axons are thought to be specialized for the sorting and transcytosis of cell type–specific ligands and receptors. However, it is not known if nonpolarized cells such as fibroblasts contain a specialized endosomal compartment analogous to the specialized endosomes found in neurons and epithelia. We have expressed a protein that is normally found in the apical early endosomes of developing intestinal epithelial cells in normal rat kidney fibroblasts. This apical endosomal marker, called endotubin, is targeted to early endosomes in transfected fibroblasts, and is present in peripheral as well as perinuclear endosomes. The peripheral endosomes that contain endotubin appear to exclude transferrin, fluid phase markers, and the mannose-6-phosphate receptor, although in the perinuclear region colocalization of endotubin and these markers is present. In addition, endotubin positive structures do not tubulate in response to brefeldin A and instead redistribute to a diffuse perinuclear location. Since this endosomal compartment has many of the characteristics of an apical or axonal endosomal compartment, our results indicate that nonpolarized cells also contain a specialized early endosomal compartment.

Abbreviations used in this paper: BFA, brefeldin A; lgp, lysosomal glycoprotein; M6PR, mannose-6-phosphate receptor; NRK, normal rat kidney.

This manuscript is dedicated to the memory of Dr. Barry King.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents