Requirements of Kettin, a giant muscle protein highly conserved in overall structure in evolution, for normal muscle function, viability, and flight activity of Drosophila.
Kettin is a giant muscle protein originally identified in insect flight muscle Z-discs. Here, we determined the entire nucleotide sequence of Drosophila melanogaster kettin, deduced the amino acid sequence of its protein product (540 kD) along with that of the Caenorhabditis elegans counterpart, and found that the overall primary structure of Kettin has been highly conserved in evolution. The main body of Drosophila Kettin consists of 35 immunoglobulin C2 domains separated by spacers. The central two thirds of spacers are constant in length and share in common two conserved motifs, putative actin binding sites. Neither fibronectin type III nor kinase domains were found. Kettin is present at the Z-disc in several muscle types. Genetic analysis showed that kettin is essential for the formation and maintenance of normal sarcomere structure of muscles and muscle tendons. Accordingly, embryos lacking kettin activity cannot hatch nor can adult flies heterozygous for the kettin mutation fly.
Hakeda
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Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
Endo
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Saigo
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans; D064211:Connectin; D018076:DNA, Complementary; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019143:Evolution, Molecular; D005426:Flight, Animal / Q000502:physiology*; D017344:Genes, Insect; D019476:Insect Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D007763:Lac Operon; D007814:Larva; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009132:Muscles / Q000196:embryology / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D011494:Protein Kinases / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D012518:Sarcomeres / Q000648:ultrastructure; D017386:Sequence Homology, Amino Acid
D064211:Connectin; D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; D009124:Muscle Proteins; D011993:Recombinant Fusion Proteins; C577347:sls protein, Drosophila; D011494:Protein Kinases