Gap junctions are specialized matched membrane domains that contain channels that allow exchange of small molecules including ions, metabolites, and second messengers (e.g., Ca2+ and IP3) between neighboring cells. These channels are necessary for proper development, and genetic linkage analyses have implicated connexins in at least 14 human diseases. The gap junction protein connexin43 (Cx43) is regulated by more than 12 phosphorylation events. The short half-life of Cx43 (~2 h) causes gap junctions to be constantly assembled, remodeled and turned over. Growth factors and wounding can further reduce Cx43's half-life and clear gap junctions from the plasma membrane within an hour in a process we term acute turnover. This proposal focuses on the role that Cx43 phosphorylation plays in gap junction stability and how acute turnover is enhanced in response to growth factors and skin wounding. We propose to: (1). determine if increased gap junction size promotes acute turnover; (2). test whether Src phosphorylation of Cx43 is necessary for GJ internalization and directs the endocytic route, and (3). determine the physiological consequences of Cx43 phosphorylation and gap junction turnover during epidermal wounding.

Public Health Relevance

Cx43 phosphorylation regulates biological responses to growth factor treatment and wound repair. Our research could have a large translational impact since Cx43 is a drug gable target currently being investigated for wound healing uses - the tissue on which we have chosen to focus our research. We hypothesize that more targeted drugs such as kinase activators or inhibitors could be topically applied in a manner dictated by the wound status (i.e., fresh, ulcerated, diabetic, etc.) to yield better healing and reduce the need for amputation.

Agency
National Institute of Health (NIH)
Type
Research Project (R01)
Project #
2R01GM055632-17A1
Application #
8759795
Study Section
Intercellular Interactions Study Section (ICI)
Program Officer
Nie, Zhongzhen
Project Start
Project End
Budget Start
Budget End
Support Year
17
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
City
Seattle
State
WA
Country
United States
Zip Code
98109
Solan, Joell L; Lampe, Paul D (2014) Specific Cx43 phosphorylation events regulate gap junction turnover in vivo. FEBS Lett 588:1423-9
Dunn, Clarence A; Lampe, Paul D (2014) Injury-triggered Akt phosphorylation of Cx43: a ZO-1-driven molecular switch that regulates gap junction size. J Cell Sci 127:455-64
Chen, Steven C; Kennedy, Brian K; Lampe, Paul D (2013) Phosphorylation of connexin43 on S279/282 may contribute to laminopathy-associated conduction defects. Exp Cell Res 319:888-96
Sakurai, Takashi; Tsuchida, Mariko; Lampe, Paul D et al. (2013) Cardiomyocyte FGF signaling is required for Cx43 phosphorylation and cardiac gap junction maintenance. Exp Cell Res 319:2152-65
Li, Dan; Sekhon, Poonampreet; Barr, Kevin J et al. (2013) Connexins and steroidogenesis in mouse Leydig cells. Can J Physiol Pharmacol 91:157-64
Marquez-Rosado, Lucrecia; Singh, Deepika; Rincon-Arano, Hector et al. (2012) CASK (LIN2) interacts with Cx43 in wounded skin and their coexpression affects cell migration. J Cell Sci 125:695-702
Dunn, Clarence A; Su, Vivian; Lau, Alan F et al. (2012) Activation of Akt, not connexin 43 protein ubiquitination, regulates gap junction stability. J Biol Chem 287:2600-7
Boassa, Daniela; Solan, Joell L; Papas, Adrian et al. (2010) Trafficking and recycling of the connexin43 gap junction protein during mitosis. Traffic 11:1471-86
del Castillo, Francisco J; Cohen-Salmon, Martine; Charollais, Anne et al. (2010) Consortin, a trans-Golgi network cargo receptor for the plasma membrane targeting and recycling of connexins. Hum Mol Genet 19:262-75
Qu, Jiaxiang; Volpicelli, Frank M; Garcia, Luis I et al. (2009) Gap junction remodeling and spironolactone-dependent reverse remodeling in the hypertrophied heart. Circ Res 104:365-71

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