A novel pancreatic beta-cell isoform of calcium/calmodulin-dependent protein kinase II (beta 3 isoform) contains a proline-rich tandem repeat in the association domain.
There is evidence for a role for calcium/calmodulin-dependent protein phosphorylation in regulation of insulin secretion but the molecular nature of the kinase(s) responsible is unknown. In this study, the screening of a neonatal rat islet cDNA library resulted in the isolation of a 2 kb clone that was 99% homologous to the beta' isoform of calcium/calmodulin-dependent protein kinase II. The predicted 589 amino acid sequence with a calculated mass of 64,976 Da contained a 24 amino acid deletion in addition to the 15 amino acid deletion that differentiates the beta' from the beta isoform, and included an 86 amino acid novel domain consisting of a tandem repeat of proline-rich residues. The expression of this new isoform of calcium/calmodulin-dependent protein kinase II (beta 3) was confirmed in beta-cell lines and testis by DNA amplification of the sequence encoding the inserted domain by reverse transcriptase-polymerase chain reaction, followed by Southern analysis.
Urquidi
V
V
Nuffield Department of Clinical Biochemistry, John Radcliffe Hospital, Headington, Oxford, UK.
Ashcroft
S J
SJ
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D007515:Islets of Langerhans / Q000201:enzymology*; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011392:Proline; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D016415:Sequence Alignment; D013737:Testis / Q000201:enzymology
D018076:DNA, Complementary; D012333:RNA, Messenger; D011392:Proline; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517676:Camk2b protein, rat