Expression of photoreceptor cyclic nucleotide-gated cation channel alpha subunit (CNGCalpha) in the liver and skeletal muscle.
Glucagon and beta-adrenergic agents increase cAMP levels and stimulate Ca2+ influx in liver cells. There is no consensus as to the mechanism by which these hormones stimulate the influx of Ca2+. Using mouse retinal rod CNGCalpha cDNA probes, we cloned rat liver and skeletal muscle, and human hepatic CNGCalpha subunit sequences showing 97-100% identity with the human rod channel. In order to assess channel activity, the effect of cyclic nucleotides on free intracellular Ca2+ levels of isolated hepatocytes was measured. Dibutyryl-cAMP was more effective in increasing free Ca2+ levels than dibutyryl-cGMP. These data indicate that the CNGCalpha subunit is expressed in both the liver and skeletal muscle possibly mediating hormonal effects on ion fluxes.
Feng
L
L
Department of Integrative Biology, University of Texas-Houston School of Medicine, USA.
Subbaraya
I
I
Yamamoto
N
N
Baehr
W
W
Kraus-Friedmann
N
N
D000595:Amino Acid Sequence; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry; D054815:Cyclic Nucleotide-Gated Cation Channels; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D007473:Ion Channels / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D008099:Liver / Q000737:chemistry* / Q000502:physiology; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D009712:Nucleotides, Cyclic / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology; D017386:Sequence Homology, Amino Acid
D054815:Cyclic Nucleotide-Gated Cation Channels; D007473:Ion Channels; D009712:Nucleotides, Cyclic; D012333:RNA, Messenger; D009599:Nitroprusside; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine; D002118:Calcium