JCB logo
Accuri Cytometers
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published online 28 December 2004. doi:10.1083/jcb.200408106
The Rockefeller University Press, 0021-9525 $8.00
JCB, Volume 168, Number 1, 79-88
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 1451K)
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 Similar articles in PubMed
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 Kota, J.
Right arrow Articles by Ljungdahl, P. O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kota, J.
Right arrow Articles by Ljungdahl, P. O.
Right arrowPubmed/NCBI databases
*Domain*Gene
*GEO Profiles*HomoloGene
*Protein
*Substance via MeSH
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?

Article

Specialized membrane-localized chaperones prevent aggregation of polytopic proteins in the ER



Jhansi Kota and Per O. Ljungdahl

Ludwig Institute for Cancer Research, S-17177 Stockholm, Sweden

Correspondence to Per O. Ljungdahl: plju{at}licr.ki.se

The integral endoplasmic reticulum (ER) membrane protein Shr3p is required for proper plasma membrane localization of amino acid permeases (AAPs) in yeast. In the absence of Shr3p AAPs are uniquely retained in the ER with each of their twelve membrane-spanning segments correctly inserted in the membrane. Here, we show that the membrane domain of Shr3p specifically prevents AAPs from aggregating, and thus, plays a critical role in assisting AAPs to fold and correctly attain tertiary structures required for ER exit. Also, we show that the integral ER proteins, Gsf2p, Pho86p, and Chs7p, function similarly to Shr3p. In cells individually lacking one of these components only their cognate substrates, hexose transporters, phosphate transporters, and chitin synthase-III, respectively, aggregate and consequently fail to exit the ER membrane. These findings indicate that polytopic membrane proteins depend on specialized membrane-localized chaperones to prevent inappropriate interactions between membrane-spanning segments as they insert and fold in the lipid bilayer of the ER membrane.

Abbreviations used in this paper: AAP, amino acid permease; DM, dodecyl-ß-D-maltopyranoside; Dpm1p, dolichol phosphate mannose synthase; DSP, Dithiobis[succinimidyl propionate]; LacY, lactose permease; PM, plasma membrane; SANPAH, N-succinimidyl 6-[4'-azido 2'-nitrophenylamino]hexanoate; SC, synthetic complex; TMS, transmembrane segments.


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