Document Detail


Connexin hemichannel composition determines the FGF-1-induced membrane permeability and free [Ca2+]i responses.
MedLine Citation:
PMID:  18495870     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cell surface hemichannels (HCs) composed of different connexin (Cx) types are present in diverse cells and their possible role on FGF-1-induced cellular responses remains unknown. Here, we show that FGF-1 transiently (4-14 h, maximal at 7 h) increases the membrane permeability through HCs in HeLa cells expressing Cx43 or Cx45 under physiological extracellular Ca(2+)/Mg(2+) concentrations. The effect does not occur in HeLa cells expressing HCs constituted of Cx26 or Cx43 with its C-terminus truncated at aa 257, or in parental nontransfected HeLa cells. The increase in membrane permeability is associated with a rise in HC levels at the cell surface and a proportional increase in HC unitary events. The response requires an early intracellular free Ca(2+) concentration increase, activation of a p38 MAP kinase-dependent pathway, and a regulatory site of Cx subunit C-terminus. The FGF-1-induced rise in membrane permeability is also associated with a late increase in intracellular free Ca(2+) concentration, suggesting that responsive HCs allow Ca(2+) influx. The cell density of Cx26 and Cx43 HeLa transfectants cultured in serum-free medium was differentially affected by FGF-1. Thus, the FGF-1-induced cell permeabilization and derived consequences depend on the Cx composition of HCs.
Authors:
Kurt A Schalper; Nicolás Palacios-Prado; Mauricio A Retamal; Kenji F Shoji; Agustín D Martínez; Juan C Sáez
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-05-21
Journal Detail:
Title:  Molecular biology of the cell     Volume:  19     ISSN:  1939-4586     ISO Abbreviation:  Mol. Biol. Cell     Publication Date:  2008 Aug 
Date Detail:
Created Date:  2008-07-29     Completed Date:  2008-12-22     Revised Date:  2013-06-05    
Medline Journal Info:
Nlm Unique ID:  9201390     Medline TA:  Mol Biol Cell     Country:  United States    
Other Details:
Languages:  eng     Pagination:  3501-13     Citation Subset:  IM    
Affiliation:
Departamento de Ciencias Fisiológicas, Pontificia Universidad Católica de Chile, Santiago, Chile. kschalpe@med.puc.cl
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MeSH Terms
Descriptor/Qualifier:
Calcium / metabolism*
Cell Membrane / metabolism
Connexin 43 / metabolism
Connexins / metabolism*
Electrophysiology
Enzyme Activation
Fibroblast Growth Factor 1 / metabolism*
HeLa Cells
Humans
Microscopy, Fluorescence
Models, Biological
Permeability*
Protein Structure, Tertiary
p38 Mitogen-Activated Protein Kinases / metabolism
Chemical
Reg. No./Substance:
0/Connexin 43; 0/Connexins; 104781-85-3/Fibroblast Growth Factor 1; 127120-53-0/connexin 26; 7440-70-2/Calcium; EC 2.7.11.24/p38 Mitogen-Activated Protein Kinases
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