Cells in most tissues are interconnected by cell-cell channels which allow the passage of electrolytes and small molecules from cell to cell. Aggregates of these channels are contained in the clustered intramembranous particles of gap junctions. The function of these channels has remained mysterious except in excitable cells where they are instrumental for impulse propagation. The objective of this research project is to understand the process of formation of cell-cell channels. This problem is addressed by functional expression of cell-cell channels in paired oocytes from cloned gap junction cDNA. With the oocyte assay conditions can be chosen where channel formation occurs at high rate (greater than 40 channel openings per second) from a pool of precursor. The oocyte assay will be used in combination with mutagenesis, synthetic peptides and the patch clamp technique to obtain information about molecular domains involved in the formation process. Channel formation at another level is proposed to be studied with gene transfer into mice (transgenics). These experiments are designed to yield information about the expression patterns of specific gap junction proteins during embryonic development. Furthermore, clues about the function of cell-cell channels in nonexcitable tissues can be expected from specific interference with gene expression.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM048610-02
Application #
2186107
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1993-01-01
Project End
1996-12-31
Budget Start
1994-01-01
Budget End
1994-12-31
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Miami School of Medicine
Department
Physiology
Type
Schools of Medicine
DUNS #
City
Miami
State
FL
Country
United States
Zip Code
33146
Samuels, Stuart E; Lipitz, Jeffrey B; Wang, Junjie et al. (2013) Arachidonic acid closes innexin/pannexin channels and thereby inhibits microglia cell movement to a nerve injury. Dev Neurobiol 73:621-31
Dahl, Gerhard; Qiu, Feng; Wang, Junjie (2013) The bizarre pharmacology of the ATP release channel pannexin1. Neuropharmacology 75:583-93
Dahl, Gerhard; Keane, Robert W (2012) Pannexin: from discovery to bedside in 11±4 years? Brain Res 1487:150-9
Qiu, Feng; Wang, Junjie; Spray, David C et al. (2011) Two non-vesicular ATP release pathways in the mouse erythrocyte membrane. FEBS Lett 585:3430-5
Ambrosi, Cinzia; Gassmann, Oliver; Pranskevich, Jennifer N et al. (2010) Pannexin1 and Pannexin2 channels show quaternary similarities to connexons and different oligomerization numbers from each other. J Biol Chem 285:24420-31
Samuels, Stuart E; Lipitz, Jeffrey B; Dahl, Gerhard et al. (2010) Neuroglial ATP release through innexin channels controls microglial cell movement to a nerve injury. J Gen Physiol 136:425-42
Wang, Junjie; Dahl, Gerhard (2010) SCAM analysis of Panx1 suggests a peculiar pore structure. J Gen Physiol 136:515-27
Qiu, Feng; Dahl, Gerhard (2009) A permeant regulating its permeation pore: inhibition of pannexin 1 channels by ATP. Am J Physiol Cell Physiol 296:C250-5
Bunse, Stefanie; Locovei, Silviu; Schmidt, Matthias et al. (2009) The potassium channel subunit Kvbeta3 interacts with pannexin 1 and attenuates its sensitivity to changes in redox potentials. FEBS J 276:6258-70
Ransford, George A; Fregien, Nevis; Qiu, Feng et al. (2009) Pannexin 1 contributes to ATP release in airway epithelia. Am J Respir Cell Mol Biol 41:525-34

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