New isoforms of Ca2+/calmodulin-dependent protein kinase II in smooth muscle.
Four novel isoforms of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) were found in rat aorta smooth muscle. Two of them were related to gamma-isoform of brain CaM kinase II (gamma-a). Differences in the primary structure of these isoforms were located in the variable region. One of them (gamma-b) contained 23 unique amino acid residues, whereas the other (gamma-c) did not contain this sequence. Both isoforms lacked the two segments (Val-316 to Gln-337 and Lys-353 to Leu-362) present in gamma-a. The DNA sequence of these gamma-isoforms except the variable region was exactly the same, suggesting that they are produced by alternative splicing. Another two isoforms were related to the delta-isoform of brain CaM kinase II (delta-a). delta-b contained a unique 11-residue sequence in the variable region whereas delta-c did not. As found for gamma-isoforms, the sequence analysis suggested that the three delta-isoforms are also produced by alternative splicing. Analysis of RNA by reverse transcription PCR confirmed the existence of specific messages for gamma-b, delta-a and delta-b. The variety of isoforms of CaM kinase II suggest that each isoform may play a specialized role in cell regulation.
Zhou
Z L
ZL
Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, OH 44106.
Ikebe
M
M
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000201:enzymology*; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis* / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers; D015723:Gene Library; D014644:Genetic Variation; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D051381:Rats; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D007527:Isoenzymes; D017871:Calcium-Calmodulin-Dependent Protein Kinases