Version 1
: Received: 11 September 2024 / Approved: 11 September 2024 / Online: 12 September 2024 (15:29:31 CEST)
How to cite:
Rastegarpouyani, H.; Hojjatian, A.; Taylor, K. A. Two Forms of Thick Filament in the Flight Muscle of Drosophila melanogaster. Preprints2024, 2024090928. https://doi.org/10.20944/preprints202409.0928.v1
Rastegarpouyani, H.; Hojjatian, A.; Taylor, K. A. Two Forms of Thick Filament in the Flight Muscle of Drosophila melanogaster. Preprints 2024, 2024090928. https://doi.org/10.20944/preprints202409.0928.v1
Rastegarpouyani, H.; Hojjatian, A.; Taylor, K. A. Two Forms of Thick Filament in the Flight Muscle of Drosophila melanogaster. Preprints2024, 2024090928. https://doi.org/10.20944/preprints202409.0928.v1
APA Style
Rastegarpouyani, H., Hojjatian, A., & Taylor, K. A. (2024). Two Forms of Thick Filament in the Flight Muscle of Drosophila melanogaster. Preprints. https://doi.org/10.20944/preprints202409.0928.v1
Chicago/Turabian Style
Rastegarpouyani, H., Alimohammad Hojjatian and Kenneth A. Taylor. 2024 "Two Forms of Thick Filament in the Flight Muscle of Drosophila melanogaster" Preprints. https://doi.org/10.20944/preprints202409.0928.v1
Abstract
Invertebrate striated muscle myosin filaments are highly variable in structure. The best characterized myosin filaments are those of insect indirect flight muscle (IFM) in which the flight powering muscles are not attached directly to the wings. Four insect orders, Hemiptera, Diptera, Hymenoptera and Coleoptera, have evolved IFM. IFM thick filaments from the first three orders have highly similar myosin arrangements but differ significantly among the non-myosin proteins. Cryo-electron microscopy of isolated IFM myosin filaments from the Dipteran Drosophila melanogaster described here reveal the coexistence of two distinct filament types. One presenting a tubular backbone like previous work, the other a solid backbone. Inside an annulus of myosin tails, tubular filaments show no noticeable densities; solid filaments show four paired paramyosin densities. Both myosin heads of tubular filaments are disordered; solid filaments have one completely and one partially immobilized head. Tubular filaments have the protein stretchin-klp on their surface; solid filaments do not. Two proteins, flightin and myofilin, are identifiable in all IFM filaments previously determined. In Drosophila, flightin assumes two conformations, compact in solid filaments, and extended in tubular filaments. Nearly identical solid filaments occur in the large water bug Lethocerus indicus, which spends most of its time under water, suggesting solid filaments conserve ATP utilizing the super relaxed state. The solid filaments in Drosophila may function similarly.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
