Novel alternative splice variants of cGMP-binding cGMP-specific phosphodiesterase.
After our recent findings that the amino-terminal portion of rat cGMP-binding, cGMP-specific phosphodiesterase (cGB-PDE) differs from those of bovine and human cGB-PDEs, we found two forms of canine cGB-PDE cDNAs (CFPDE5A1 and CFPDE5A2) in canine lung. Each contained a distinct amino-terminal sequence, CFPDE5A1, possessing an amino-terminal portion with sequence similar to those of bovine and human, and CFPDE5A2, having one similar to that of rat. Other portions coding for the cGMP binding domains and the catalytic domain were conserved. Both CFPDE5A1 and CFPDE5A2 transcripts were detected in the cerebellum, hippocampus, retina, lung, heart, spleen, and thoracic artery. CFPDE5A1 transcripts were particularly abundant in the pylorus, whereas CFPDE5A2 transcripts were quite low in this tissue. CFPDE5A1 and CFPDE5A2 expressed in COS-7 cells had cGMP Km values of 2.68 and 1.97 microM, respectively, and both were inhibited by a low concentration of a cGB-PDE inhibitor, Zaprinast. Both CFPDE5A1 and CFPDE5A2 bound cGMP to their allosteric cGMP binding domains, and this cGMP binding was stimulated by 3-isobutyl-1-methylxanthine. Thus, two types of alternative splice variants of canine cGB-PDE have been identified and shown to have similar biological properties in vitro.
Discovery Research Laboratory, Tanabe Seiyaku Co. Ltd., 2-50, Kawagishi-2-chome, Toda, Saitama, 335-8505, Japan.
J
J
Kotera
K
K
Fujishige
H
H
Akatsuka
Y
Y
Imai
N
N
Yanaka
K
K
Omori
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D003001:Cloning, Molecular; D006152:Cyclic GMP / Q000378:metabolism*; D017931:DNA Primers; D004285:Dogs; D006801:Humans; D007700:Kinetics; D008297:Male; D008969:Molecular Sequence Data; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism
D017931:DNA Primers; D010726:Phosphodiesterase Inhibitors; D011994:Recombinant Proteins; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D006152:Cyclic GMP