![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
|
|
|
|
|
||
A more recent version of this article appeared on November 1, 2005
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on May 11, 2005
Revised on August 11, 2005
Accepted on August 19, 2005
Division of Molecular Medicine, Oregon Health & Science University, Portland, OR 97239
Monitoring Editor: Asma Nusrat
The protein constituents of gap junctions, connexins, have a rapid basal rate of degradation even after transport to the cell surface. We have used cell surface biotinylation to label gap junction-unassembled plasma membrane pools of connexin43 (Cx43) and show that their degradation is inhibited by mild hyperthermia, oxidative stress, and proteasome inhibitors. Cytosolic stress does not perturb endocytosis of biotinylated Cx43, but instead appears to interfere with its targeting and/or transport to the lysosome, possibly by increasing the level of unfolded protein in the cytosol. This allows more Cx43 molecules to recycle to the cell surface, where they are assembled into long-lived, functional gap junctions in otherwise gap junction assembly-inefficient cells. Cytosolic stress also slowed degradation of biotinylated Cx43 in gap junction assembly-efficient NRK fibroblasts, and reduced the rate at which gap junctions disappeared from cell interfaces under conditions that blocked transport of nascent connexin molecules to the plasma membrane. These data demonstrate that degradation from the cell surface can be down-regulated by physiologically relevant forms of stress. For connexins, this may serve to enhance or preserve gap junction-mediated intercellular communication even under conditions in which protein synthesis and/or intracellular transport are compromised.
This article has been cited by other articles:
|
|
 |
|
  K. A. Schalper, N. Palacios-Prado, M. A. Retamal, K. F. Shoji, A. D. Martinez, and J. C. Saez Connexin Hemichannel Composition Determines the FGF-1-induced Membrane Permeability and Free [Ca2+]i Responses Mol. Biol. Cell, August 1, 2008; 19(8): 3501 - 3513. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A.-S. Zhang, F. Yang, K. Meyer, C. Hernandez, T. Chapman-Arvedson, P. J. Bjorkman, and C. A. Enns Neogenin-mediated Hemojuvelin Shedding Occurs after Hemojuvelin Traffics to the Plasma Membrane J. Biol. Chem., June 20, 2008; 283(25): 17494 - 17502. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. H.-C. Lin, N. Lou, N. Kang, T. Takano, F. Hu, X. Han, Q. Xu, D. Lovatt, A. Torres, K. Willecke, et al. A Central Role of Connexin 43 in Hypoxic Preconditioning J. Neurosci., January 16, 2008; 28(3): 681 - 695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Mitra, L. Annamalai, S. Chakraborty, K. Johnson, X.-H. Song, S. K. Batra, and P. P. Mehta Androgen-regulated Formation and Degradation of Gap Junctions in Androgen-responsive Human Prostate Cancer Cells Mol. Biol. Cell, December 1, 2006; 17(12): 5400 - 5416. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Retamal, C. J. Cortes, L. Reuss, M. V. L. Bennett, and J. C. Saez S-nitrosylation and permeation through connexin 43 hemichannels in astrocytes: Induction by oxidant stress and reversal by reducing agents PNAS, March 21, 2006; 103(12): 4475 - 4480. [Abstract] [Full Text] [PDF]
|
|
