|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molecular & Cellular Proteomics 6:1855-1867, 2007.
© 2007 by The American Society for Biochemistry and Molecular Biology, Inc.

From the Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute and the Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115
Tetraspanins serve as molecular organizers of multiprotein microdomains in cell membranes. Hence to understand functions of tetraspanin proteins, it is critical to identify laterally interacting partner proteins. Here we used a novel technical approach involving exposure and cross-linking of membrane-proximal cysteines coupled with LC-MS/MS protein identification. In this manner we identified nine potential tetraspanin CD9 partners, including claudin-1. Chemical cross-linking yielded a CD9-claudin-1 heterodimer, thus confirming direct association and adding claudin-1 to the short list of proteins that can directly associate with CD9. Interaction of CD9 (and other tetraspanins) with claudin-1 was supported by subcellular colocalization and was confirmed in multiple cell lines, although other claudins (claudin-2, -3, -4, -5, and -7) associated to a much lesser extent. Moreover claudin-1 was distributed very similarly to CD9 in sucrose gradients and, like CD9, was released from A431 and A549 cells upon cholesterol depletion. These biochemical features of claudin-1 are characteristic of tetraspanin microdomain proteins. Although claudins are major structural components of intercellular tight junctions, CD9-claudin-1 complexes did not reside in tight junctions, and depletion of key tetraspanins (CD9 and CD151) by small interfering RNA had no effect on paracellular permeability. However, tetraspanin depletion did cause a marked decrease in the stability of newly synthesized claudin-1. In conclusion, these results (a) validate a technical approach that appears to be particularly well suited for identifying protein partners directly associated with tetraspanins or with other proteins that contain membrane-proximal cysteines and (b) provide insight into how non-junctional claudins may be regulated in the context of tetraspanin-enriched microdomains.
To whom correspondence should be addressed: Dana-Farber Cancer Inst., D-1430, 44 Binney St., Boston, MA 02115. Tel.: 617-632-3410; Fax: 617-632-2662
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
C. Sharma, X. H. Yang, and M. E. Hemler DHHC2 Affects Palmitoylation, Stability, and Functions of Tetraspanins CD9 and CD151 Mol. Biol. Cell, August 1, 2008; 19(8): 3415 - 3425. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. J. Harris, M. J. Farquhar, C. J. Mee, C. Davis, G. M. Reynolds, A. Jennings, K. Hu, F. Yuan, H. Deng, S. G. Hubscher, et al. CD81 and Claudin 1 Coreceptor Association: Role in Hepatitis C Virus Entry J. Virol., May 15, 2008; 82(10): 5007 - 5020. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. H. Yang, A. L. Richardson, M. I. Torres-Arzayus, P. Zhou, C. Sharma, A. R. Kazarov, M. M. Andzelm, J. L. Strominger, M. Brown, and M. E. Hemler CD151 Accelerates Breast Cancer by Regulating {alpha}6 Integrin Function, Signaling, and Molecular Organization Cancer Res., May 1, 2008; 68(9): 3204 - 3213. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Yang, C. Qiu, N. Biswas, J. Jin, S. C. Watkins, R. C. Montelaro, C. B. Coyne, and T. Wang Correlation of the Tight Junction-like Distribution of Claudin-1 to the Cellular Tropism of Hepatitis C Virus J. Biol. Chem., March 28, 2008; 283(13): 8643 - 8653. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Journal of Lipid Research | ASBMB Today |