J. Cell Biol.
© The Rockefeller University Press
0021-9525/97/04/203/08 $2.00
Volume 137, Number 1, April 7, 1997 203-210

A Mitosis-specific Phosphorylation of the Gap Junction Protein Connexin43 in Human Vascular Cells: Biochemical Characterization and Localization

Han-qing Xie,^* Dale W. Laird, Tsg-Hui Chang,^* and Valerie W. Hu^*

^* Department of Biochemistry and Molecular Biology, The George Washington University, Washington, DC, 20037; and  Department of Anatomy and Cell Biology, McGill University, Montreal, Canada H3A-2B2

Western blotting studies revealed that connexin43 (Cx43), one of the major gap junction proteins in human vascular endothelial cells, is posttranslationally modified during mitosis. This mitosis-specific modification results in a Cx43 species that migrates as a single protein band and was designated Cx43_m. Cx43_m was shown to be the result of additional Ser/Thr phosphorylation as indicated by: (a) the increased gel mobility induced by both alkaline phosphatase and the Ser/ Thr-specific protein phosphatase-2A (PP2A) and (b) the removal of virtually all ³²P_i from Cx43_m by PP2A. Immunofluorescent confocal microscopy of mitotic cells revealed that Cx43 is intracellularly located, while in nonmitotic cells Cx43 is located at regions of cell-cell contact. Dye coupling studies revealed that mitotic endothelial cells were uncoupled from each other and from nonmitotic cells. After cytokinesis, sister cells resumed cell coupling independent of de novo protein synthesis. The mitosis-specific phosphorylation of Cx43 correlates with the transient loss of gap junction intercellular communication and redistribution of Cx43, suggesting that a protein kinase that regulates gap junctions is active in M-phase.

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

This article has been cited by other articles:

• Figueroa, X. F., Isakson, B. E., Duling, B. R. (2006). Vascular Gap Junctions in Hypertension. Hypertension 48: 804-811 [Full Text]  
• Isakson, B. E., Kronke, G., Kadl, A., Leitinger, N., Duling, B. R. (2006). Oxidized Phospholipids Alter Vascular Connexin Expression, Phosphorylation, and Heterocellular Communication. Arterioscler. Thromb. Vasc. Bio. 26: 2216-2221 [Abstract] [Full Text]  
• Mehta, D., Malik, A. B. (2006). Signaling Mechanisms Regulating Endothelial Permeability. Physiol. Rev. 86: 279-367 [Abstract] [Full Text]  
• Solan, J. L., Fry, M. D., TenBroek, E. M., Lampe, P. D. (2003). Connexin43 phosphorylation at S368 is acute during S and G2/M and in response to protein kinase C activation. J. Cell Sci. 116: 2203-2211 [Abstract] [Full Text]  
• Koval, M. (2002). Sharing signals: connecting lung epithelial cells with gap junction channels. Am. J. Physiol. Lung Cell. Mol. Physiol. 283: L875-L893 [Abstract] [Full Text]  
• Garcia-Dorado, D., Ruiz-Meana, M., Padilla, F., Rodriguez-Sinovas, A., Mirabet, M. (2002). Gap junction-mediated intercellular communication in ischemic preconditioning. Cardiovasc Res 55: 456-465 [Abstract] [Full Text]  
• Suarez, S, Ballmer-Hofer, K (2001). VEGF transiently disrupts gap junctional communication in endothelial cells. J. Cell Sci. 114: 1229-1235 [Abstract]  
• Kimura, S., Suzuki, K., Sagara, T., Nishida, T., Yamamoto, T., Kitazawa, Y. (2000). Regulation of Connexin Phosphorylation and Cell-Cell Coupling in Trabecular Meshwork Cells. IOVS 41: 2222-2228 [Abstract] [Full Text]  
• Toyofuku, T., Yabuki, M., Otsu, K., Kuzuya, T., Tada, M., Hori, M. (1999). Functional Role of c-Src in Gap Junctions of the Cardiomyopathic Heart. Circ. Res. 85: 672-681 [Abstract] [Full Text]  
• Ko, Y.-S., Yeh, H.-I, Rothery, S., Dupont, E., Coppen, S. R., Severs, N. J. (1999). Connexin Make-up of Endothelial Gap Junctions in the Rat Pulmonary Artery as Revealed by Immunoconfocal Microscopy and Triple-label Immunogold Electron Microscopy. J. Histochem. Cytochem. 47: 683-692 [Abstract] [Full Text]  
• Zhou, L., Kasperek, E. M., Nicholson, B. J. (1999). Dissection of the Molecular Basis of pp60v-src Induced Gating of Connexin 43 Gap Junction Channels. JCB 144: 1033-1045 [Abstract] [Full Text]  
• Kim, D. Y., Kam, Y., Koo, S. K., Joe, C. O. (1999). Gating Connexin 43 Channels Reconstituted in Lipid Vesicles by Mitogen-activated Protein Kinase Phosphorylation. J. Biol. Chem. 274: 5581-5587 [Abstract] [Full Text]  
• Yeh, H.-I, Rothery, S., Dupont, E., Coppen, S. R., Severs, N. J. (1998). Individual Gap Junction Plaques Contain Multiple Connexins in Arterial Endothelium. Circ. Res. 83: 1248-1263 [Abstract] [Full Text]  
• Lampe, P., Kurata, W., Warn-Cramer, B., Lau, A. (1998). Formation of a distinct connexin43 phosphoisoform in mitotic cells is dependent upon p34cdc2 kinase. J. Cell Sci. 111: 833-841 [Abstract]  
• Ou, C.-W., Orsino, A., Lye, S. J. (1997). Expression of Connexin-43 and Connexin-26 in the Rat Myometrium during Pregnancy and Labor Is Differentially Regulated by Mechanical and Hormonal Signals. Endocrinology 138: 5398-5407 [Abstract] [Full Text]  

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