Flightin, a novel myofibrillar protein of Drosophila stretch-activated muscles

• Published in: The Journal of cell biology Vol. 121; no. 3; pp. 587 - 598
• Main Authors: Vigoreaux, Jim O., Saide, Judith D., Valgeirsdottir, Katrin, Pardue, Mary Lou
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.05.1993; The Rockefeller University Press
• Subjects: Actins; Actins - chemistry; aile; alas; Amino Acid Sequence; Amino acids; Animals; Base Sequence; biochemical polymorphism; Biochemistry. Physiology. Immunology; Biological and medical sciences; Cellular biology; Complementary DNA; Diptera; Drosophila; Drosophila melanogaster; Drosophila melanogaster - genetics; Drosophila Proteins; Drosophilidae; Filamins; Flight muscles; Flight, Animal; Fundamental and applied biological sciences. Psychology; Gels; gene; genes; Insecta; Insects; Invertebrates; locomocion; locomotion; Molecular Sequence Data; muscle; Muscle Contraction; Muscle Proteins - chemistry; Muscle Proteins - genetics; Muscles; musculos; Myosins - chemistry; nucleotide sequence; Physiology. Development; polimorfismo bioquimico; polymorphisme biochimique; Protein isoforms; Protein Processing, Post-Translational; proteinas; proteine; Proteins; RNA; secuencia nucleica; sequence nucleique; wings; Molecular form; Myofibril; Insecta; Flight; Striated muscle; Drosophilidae; Proteins; Arthropoda; Invertebrata; Localization; Drosophila melanogaster; Diptera; Stretching
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.121.3.587

The indirect flight muscles of Drosophila are adapted for rapid oscillatory movements which depend on properties of the contractile apparatus itself. Flight muscles are stretch activated and the frequency of contraction in these muscles is independent of the rate of nerve impulses. Little is known about the molecular basis of these adaptations. We now report a novel protein that is found only in flight muscles and has, therefore, been named flightin. Although we detect only one gene (in polytene region 76D) for flightin, this protein has several isoforms (relative gel mobilities, 27-30 kD; pIs, 4.6-6.0). These isoforms appear to be created by posttranslational modifications. A subset of these isoforms is absent in newly emerged adults but appears when the adult develops the ability to fly. In intact muscles flightin is associated with the A band of the sarcomere, where evidence suggests it interacts with the myosin filaments. Computer database searches do not reveal extensive similarity to any known protein. However, the NH2-terminal 12 residues show similarity to the NH2-terminal sequence of actin, a region that interacts with myosin. These features suggest a role for flightin in the regulation of contraction, possibly by modulating actin-myosin interaction.