HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 280, Issue 23, 22081-22090, June 10, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/23/22081    most recent M414377200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend 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 Yu, X. S. Articles by Jiang, J. X. Search for Related Content PubMed PubMed Citation Articles by Yu, X. S. Articles by Jiang, J. X. Social Bookmarking                      What's this?

Developmental Regulation of the Direct Interaction between the Intracellular Loop of Connexin 45.6 and the C Terminus of Major Intrinsic Protein (Aquaporin-0)^*

Xun Sean Yu, Xinye Yin, Eileen M. Lafer, and Jean X. Jiang

From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229-3900

The eye lens is dependent upon a network of gap junction-mediated intercellular communication to facilitate its homeostasis and development. Three gap junction-forming proteins are expressed in the lens of which two are in lens fibers, namely connexin (Cx) 45.6 and 56. Major intrinsic protein (MIP), also known as aquaporin-0 (AQP0), is the most abundant membrane protein in lens fibers. However, its role in the lens is not clear. Our previous studies show that MIP(AQP0) associates with gap junction plaques formed by Cx45.6 and Cx56 during the early stages of embryonic chick lens development but not in late embryonic and adult lenses. We report here that MIP(AQP0) directly interacts with Cx45.6 but not with Cx56. We further identified the intracellular loop of Cx45.6 as the interacting domain for the MIP(AQP0) C terminus. Surface plasmon resonance experiments indicated that the C-terminal domain of MIP(AQP0) interacts with two binding sites within the intracellular loop region of Cx45.6 with a K_D(app) of 7.5 and 10.3 µM, respectively. The K_D(app) for the full-length loop region is 7.7 µM. The cleavage at the intracellular loop of Cx45.6 was observed during lens development, and the C terminus of MIP(AQP0) did not interact with the loop-cleaved form of Cx45.6. Thus, the dissociation between these two proteins that occurs in the mature fibers of late lens development is likely caused by this cleavage. Finally this interaction had no impact on Cx45.6-mediated intercellular communication, suggesting that the Cx45.6-MIP(AQP0) interaction plays a novel unidentified role in lens fibers.

Received for publication, December 21, 2004 , and in revised form, March 16, 2005.

^* This work was supported by National Institutes of Health Grant EY12085 and Welch Foundation Grant AQ-1507 (to J. X. J.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

To whom correspondence should be addressed: Dept. of Biochemistry, MSC 7760, University of Texas Health Science Center, 7703 Floyd Curl Dr., San Antonio, TX 78229-3900. Tel.: 210-567-3796; Fax: 210-567-6595; E-mail: jiangj{at}uthscsa.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				D. Shearer, W. Ens, K. Standing, and G. Valdimarsson Posttranslational Modifications in Lens Fiber Connexins Identified by Off-Line-HPLC MALDI-Quadrupole Time-of-Flight Mass Spectrometry Invest. Ophthalmol. Vis. Sci., April 1, 2008; 49(4): 1553 - 1562. [Abstract] [Full Text] [PDF]

				R. Farjo, W. M. Peterson, and M. I. Naash Expression Profiling after Retinal Detachment and Reattachment: A Possible Role for Aquaporin-0 Invest. Ophthalmol. Vis. Sci., February 1, 2008; 49(2): 511 - 521. [Abstract] [Full Text] [PDF]

				D. Lin, M. Barnett, S. Lobell, D. Madgwick, D. Shanks, L. Willard, G. A. Zampighi, and D. J. Takemoto PKC{gamma} knockout mouse lenses are more susceptible to oxidative stress damage J. Exp. Biol., November 1, 2006; 209(21): 4371 - 4378. [Abstract] [Full Text] [PDF]

				K. M. L. Rose, R. G. Gourdie, A. R. Prescott, R. A. Quinlan, R. K. Crouch, and K. L. Schey The C Terminus of Lens Aquaporin 0 Interacts with the Cytoskeletal Proteins Filensin and CP49. Invest. Ophthalmol. Vis. Sci., April 1, 2006; 47(4): 1562 - 1570. [Abstract] [Full Text] [PDF]