Sequence comparison of the 63-, 61-, and 59-kDa calmodulin-dependent cyclic nucleotide phosphodiesterases.
Partial protein sequences from the 59-kDa bovine heart and the 63-kDa bovine brain calmodulin-dependent phosphodiesterases (CaM-PDEs) were determined and compared to the sequence of the 61-kDa isozyme reported by Charbonneau et al. [Charbonneau, H., Kumar, S., Novack, J. P., Blumenthal, D. K., Griffin, P. R., Shabanowitz, J., Hunt, D. F., Beavo, J. A. & Walsh, K. A. (1991) Biochemistry (preceding paper in this issue)]. Only a single segment (34 residues) at the N-terminus of the 59-kDa isozyme lacks identity with the 61-kDa isozyme; all other assigned sequence is identical in the two isozymes. Peptides from the 59-kDa isozyme that correspond to residues 23-41 of the 61-kDa protein bind calmodulin with high affinity. The C-terminal halves of these calmodulin-binding peptides are identical to the corresponding 59-kDa sequence; the N-terminal halves differ. The localization of sequence differences within this single segment suggests that the 61- and 59-kDa isozymes are generated from a single gene by tissue-specific alternative RNA splicing. In contrast, partial sequence from the 63-kDa bovine brain CaM-PDE isozyme displays only 67% identity with the 61-kDa isozyme. The differences are dispersed throughout the sequence, suggesting that the 63- and 61-kDa isozymes are encoded by separate but homologous genes.
Novack
J P
JP
Department of Pharmacology, University of Washington, Seattle 98195.
Charbonneau
H
H
Bentley
J K
JK
Walsh
K A
KA
Beavo
J A
JA
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology*; D002147:Calmodulin / Q000378:metabolism; D002417:Cattle; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D010450:Endopeptidases; D007527:Isoenzymes / Q000235:genetics*; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009206:Myocardium / Q000201:enzymology*; D010446:Peptide Fragments / Q000302:isolation & purification; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology; D012689:Sequence Homology, Nucleic Acid
D002147:Calmodulin; D007527:Isoenzymes; D010446:Peptide Fragments; D010455:Peptides; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D010450:Endopeptidases