TY - JOUR
T1 - Molecular characterization and functional expression if the human cardiac gap junction channel
AU - Fishman, Glenn I.
AU - Spray, David C.
AU - Leinwand, Leslie A.
PY - 1990/8
Y1 - 1990/8
N2 - Gap junctions permit the passage of ions and chemical mediators from cell to cell. To identify he molecular genetic basis for this coupling in the human heart, we have isolated clones from a human fetal cardiac cDNA library which encode the full-length human cardiac gap junction (HCGJ) mRNA. The predicted amino acid sequence is homologous to the rat cardiac gap junction protein, connexin43 (Beyer, E. D., D. Paul, and D. A. Goodenough. 1987. J. Cell Biol. 105:2621-2629.), differing by 9 of 382 amino acids. HCGJ mRNA is detected as early as fetal week 15 and persists in adult human cardiac samples. Genomic DNA analysis suggests the presence of two highly homologous HCGJ loci, only one of which is functional. Stable transfection of the HCGJ cDNA into SKHepl cells, a human hepatoma line which is communication deficient, leads to the formation of functional channels. Junctional conductance in pairs of transfectants containing 10 copies of the HCGJ sequence is high (∼20 nS). Single channel currents are detectable in this expression system and correspond to conductances of ∼60 pS. These first measurements of the HCGJ channel are similar to the Junctional conductance recorded between pairs of rat or guinea pig cardiocytes.
AB - Gap junctions permit the passage of ions and chemical mediators from cell to cell. To identify he molecular genetic basis for this coupling in the human heart, we have isolated clones from a human fetal cardiac cDNA library which encode the full-length human cardiac gap junction (HCGJ) mRNA. The predicted amino acid sequence is homologous to the rat cardiac gap junction protein, connexin43 (Beyer, E. D., D. Paul, and D. A. Goodenough. 1987. J. Cell Biol. 105:2621-2629.), differing by 9 of 382 amino acids. HCGJ mRNA is detected as early as fetal week 15 and persists in adult human cardiac samples. Genomic DNA analysis suggests the presence of two highly homologous HCGJ loci, only one of which is functional. Stable transfection of the HCGJ cDNA into SKHepl cells, a human hepatoma line which is communication deficient, leads to the formation of functional channels. Junctional conductance in pairs of transfectants containing 10 copies of the HCGJ sequence is high (∼20 nS). Single channel currents are detectable in this expression system and correspond to conductances of ∼60 pS. These first measurements of the HCGJ channel are similar to the Junctional conductance recorded between pairs of rat or guinea pig cardiocytes.
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U2 - 10.1083/jcb.111.2.589
DO - 10.1083/jcb.111.2.589
M3 - Article
C2 - 1696265
AN - SCOPUS:0025334411
SN - 0021-9525
VL - 111
SP - 589
EP - 598
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 2
ER -