Determination and cellular localization of adenylyl cyclase isozymes expressed in embryonic chick heart.
Mammalian heart has been reported to express AC isozymes (types V and VI) that are inhibited by < microM [Ca2+]; avian heart has been reported to express adenylyl cyclase activity that is inhibited by < microM [Ca2]. We have used reverse transcription polymerase chain reaction (RT-PCR) to determine that type V and VI AC mRNAs are present in freshly isolated ventricular myocytes. Subsequent RNase protection assays revealed that that the type V signal is 4-5 times that for the type VI isozyme. In situ hybridization with high specific activity cRNA probes combined with immunocytochemistry with a chick anti-myosin antibody was used to probe the cellular origins of type V and type VI AC signals. These studies show that myocytes contain messages for both the type V and VI isozymes but that AC V is the major isoform. Interestingly, while the type V AC mRNA appears to be localized primarily, if not exclusively, in myocytes, the signal for type AC VI mRNA in non-myocytes is stronger than in myocytes.
Yu
H J
HJ
Department of Pharmacology, University of Illinois at Chicago 60612, USA.
Unnerstall
J R
JR
Green
R D
RD
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002642:Chick Embryo; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D006352:Heart Ventricles / Q000196:embryology; D017403:In Situ Hybridization; D007527:Isoenzymes / Q000378:metabolism*; D008969:Molecular Sequence Data; D009206:Myocardium / Q000166:cytology / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D012260:Ribonucleases; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D017931:DNA Primers; D007527:Isoenzymes; D012260:Ribonucleases; D000262:Adenylyl Cyclases