Molecular cloning of a novel protein containing the association domain of calmodulin-dependent protein kinase II.
The cDNA of a novel protein, which contains the association domain of alpha isoform of calmodulin-dependent protein kinase II (CaM-kinase II alpha), was cloned from rat skeletal muscle. This protein, called alpha KAP, consisted of 200 amino acid residues with a molecular weight of 22,583. alpha KAP has a highly hydrophobic amino-terminal stretch of 25 amino acids which is absent from CaM-kinase II alpha, suggesting that this protein is either a secretory protein or an integral membrane protein. Northern blot analysis with a probe specific for alpha KAP detected three distinct mRNA species of 4.0, 2.4, and 1.5 kb in rat skeletal muscle. The 4.0- and 2.4-kb RNAs were also detected in heart, and at much lower levels in lung, kidney, and testis. Western blot analysis, using antibody raised against a synthetic peptide corresponding to the carboxyl-terminal 15 amino acids, revealed a single band corresponding in mobility to a molecular weight of 21,000 in crude extracts of both rat skeletal muscle and bacteria transformed with the cDNA, suggesting that no significant post-translational modification, such as excision of the amino-terminal hydrophobic segment, occurred. This, together with the fact that alpha KAP was recovered in the high-speed pellet in skeletal muscle, indicated that this protein may be an integral membrane protein.
Sugai
R
R
Department of Biochemistry, Asahikawa Medical College, Hokkaido.
Takeuchi
M
M
Okuno
S
S
Fujisawa
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D013347:Subcellular Fractions / Q000737:chemistry; D014158:Transcription, Genetic
D018076:DNA, Complementary; D007527:Isoenzymes; D012333:RNA, Messenger; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases