Cryoelectron Tomography of Isolated, Relaxed Thick Filaments from Lethocerus Indicus Flight Muscle

Striated muscle thick filaments are composed of myosin II and several non-myosin proteins. Myosin II’s long α-helical coiled-coil tail forms the dense protein backbone of filaments, whereas its N-terminal globular head containing the catalytic and actin-binding activities extends outward from the backbone. Here, we report the structure of thick filaments of the flight muscle of the fruit fly Drosophila melanogaster at 7 Å resolution. Its myosin tails are arranged in curved molecular crystalline layers identical to flight muscles of the giant water bug Lethocerus indicus. Four non-myosin densities are observed, three of which correspond to ones found in Lethocerus; one new density, possibly stretchin-mlck, is found on the backbone outer surface. Surprisingly, the myosin heads are disordered rather than ordered along the filament backbone. Our results show striking myosin tail similarity within flight muscle filaments of two insect orders separated by several hundred million years of evolution.

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CryoEM Structure of Drosophila Flight Muscle Thick Filaments at 7Å Resolution

10.1101/2020.06.05.136580 ◽

2020 ◽

Author(s):

Nadia Daneshparvar ◽

Dianne W. Taylor ◽

Thomas S. O’Leary ◽

Hamidreza Rahmani ◽

Fatemeh Abbasi Yeganeh ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Striated Muscle ◽

Flight Muscle ◽

Coiled Coil ◽

Thick Filament ◽

Fruit Fly ◽

Actin Binding ◽

Thick Filaments ◽

Flight Muscles ◽

Lethocerus Indicus

AbstractStriated muscle thick filaments are composed of myosin II and several non-myosin proteins. Myosin II’s long α-helical coiled-coil tail forms the dense protein backbone of filaments while its N-terminal globular head containing the catalytic and actin binding activities extends outward from the backbone. Here we report the structure of thick filaments of the flight muscle of the fruit fly Drosophila melanogaster at 7 Å resolution. Its myosin tails are arranged in curved molecular crystalline layers identical to flight muscles of the giant waterbug Lethocerus indicus. Four non-myosin densities are observed, three of which correspond to ones found in Lethocerus; one new density, possibly stretchin-Mlck, is found on the backbone outer surface. Surprisingly, the myosin heads are disordered rather than ordered along the filament backbone. Our results show striking myosin tail similarity within flight muscle filaments of two insect orders separated by several hundred million years of evolution.Significance StatementMyosin thick filaments are one of striated muscle’s key structures, but also one of its least understood. A key question is how the myosin a-helical coiled-coil tail is arranged in the backbone. At 7Å resolution, sufficient to resolve individual a-helices, the myosin tail arrangement in thick filaments from the flight muscle of the fruit fly Drosophila melanogaster is strikingly similar to the myosin tail arrangement in flight muscles of the giant waterbug Lethocerus indicus. Nearly every other thick filament feature is different. Drosophila and Lethocerus evolved separately >245 million years ago suggesting myosin tail packing into curved molecular crystalline layers forms a highly conserved thick filament building block and different properties are obtained by alterations in non-myosin proteins.

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Characterization of components of Z-bands in the fibrillar flight muscle of Drosophila melanogaster.

The Journal of Cell Biology ◽

10.1083/jcb.109.5.2157 ◽

1989 ◽

Vol 109 (5) ◽

pp. 2157-2167 ◽

Cited By ~ 78

Author(s):

J D Saide ◽

S Chin-Bow ◽

J Hogan-Sheldon ◽

L Busquets-Turner ◽

J O Vigoreaux ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Monoclonal Antibodies ◽

Flight Muscle ◽

Cross Reactivity ◽

Antigenic Determinants ◽

Immunogold Staining ◽

Thick Filaments ◽

The Matrix ◽

Flight Muscles

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots of myofibrillar proteins. Monoclonal antibodies alpha:1-4 recognize a 90-100-kD protein which we identify as alpha-actinin on the basis of cross-reactivity with antibodies raised against honeybee and vertebrate alpha-actinins. Monoclonal antibodies P:1-4 bind to the high molecular mass protein, projectin, a component of connecting filaments that link the ends of thick filaments to the Z-band in insect asynchronous flight muscles. The anti-projectin antibodies also stain synchronous muscle, but, surprisingly, the epitopes here are within the A-bands, not between the A- and Z-bands, as in flight muscle. Monoclonal antibodies Z(210):1-4 recognize a 210-kD protein that has not been previously shown to be a Z-band structural component. A fourth antigen, resolved as a doublet (approximately 400/600 kD) on immunoblots of Drosophila fibrillar proteins, is detected by a cross reacting antibody, Z(400):2, raised against a protein in isolated honeybee Z-disks. On Lowicryl sections of asynchronous flight muscle, indirect immunogold staining has localized alpha-actinin and the 210-kD protein throughout the matrix of the Z-band, projectin between the Z- and A-bands, and the 400/600-kD components at the I-band/Z-band junction. Drosophila alpha-actinin, projectin, and the 400/600-kD components share some antigenic determinants with corresponding honeybee proteins, but no honeybee protein interacts with any of the Z(210) antibodies.

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Molecular and ultrastructural defects in a Drosophila myosin heavy chain mutant: differential effects on muscle function produced by similar thick filament abnormalities.

The Journal of Cell Biology ◽

10.1083/jcb.107.6.2601 ◽

1988 ◽

Vol 107 (6) ◽

pp. 2601-2612 ◽

Cited By ~ 65

Author(s):

P T O'Donnell ◽

S I Bernstein

Keyword(s):

Myosin Heavy Chain ◽

Heavy Chain ◽

Muscle Function ◽

Flight Muscle ◽

Thick Filament ◽

Differential Sensitivity ◽

Indirect Flight Muscle ◽

Molecular Defect ◽

Thick Filaments ◽

Nuclease Mapping

We have determined the molecular defect of the Drosophila melanogaster myosin heavy chain (MHC) mutation Mhc and the mutation's effect on indirect flight muscle, jump muscle, and larval intersegmental muscle. We show that the Mhc1 mutation is essentially a null allele which results in the dominant-flightless and recessive-lethal phenotypes associated with this mutant (Mogami, K., P. T. O'Donnell, S. I. Bernstein, T. R. F. Wright, C. P. Emerson, Jr. 1986. Proc. Natl. Acad. Sci. USA. 83:1393-1397). The mutation is a 101-bp deletion in the MHC gene which removes most of exon 5 and the intron that precedes it. S1 nuclease mapping indicates that mutant transcripts follow two alternative processing pathways. Both pathways result in the production of mature transcripts with altered reading frames, apparently yielding unstable, truncated MHC proteins. Interestingly, the preferred splicing pathway uses the more distal of two available splice donor sites. We present the first ultrastrutural characterization of a completely MHC-null muscle and show that it lacks any discernable thick filaments. Sarcomeres in these muscles are completely disorganized suggesting that thick filaments play a critical role in sarcomere assembly. To understand why the Mhc1 mutation severely disrupts indirect flight muscle and jump muscle function in heterozygotes, but does not seriously affect the function of other muscle types, we examined the muscle ultrastructure of Mhc1/+ heterozygotes. We find that these organisms have a nearly 50% reduction in the number of thick filaments in indirect flight muscle, jump muscle, and larval intersegmental muscle. In addition, aberrantly shaped thick filaments are common in the jump muscle and larval intersegmental muscle. We suggest that the differential sensitivity of muscle function to the Mhc1 mutation is a consequence of the unique myofilament arrays in each of these muscles. The highly variable myofilament array of larval intersegmental muscle makes its function relatively insensitive to changes in thick filament number and morphology. Conversely, the rigid double hexagonal lattice of the indirect flight muscle, and the organized lattice of the jump muscle cannot be perturbed without interfering with the specialized and evolutionarily more complex functions they perform.

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The continuity of thick filaments between sarcomeres in honey bee flight muscle

Nature ◽

10.1038/281319a0 ◽

1979 ◽

Vol 281 (5729) ◽

pp. 319-320 ◽

Cited By ~ 7

Author(s):

K. Trombitas ◽

A. Tigyi-Sebes

Keyword(s):

Honey Bee ◽

Flight Muscle ◽

Thick Filaments

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Structure of Thick Filaments from Drosophila Indirect Flight Muscle by Cryo-EM

Biophysical Journal ◽

10.1016/j.bpj.2018.11.2182 ◽

2019 ◽

Vol 116 (3) ◽

pp. 404a

Author(s):

Nadia Daneshparvar ◽

Dianne Taylor ◽

Hamidreza Rahmani ◽

Kenneth A. Taylor

Keyword(s):

Flight Muscle ◽

Indirect Flight Muscle ◽

Thick Filaments

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THE STRUCTURE OF INTERSEGMENTAL MUSCLE FIBERS IN AN INSECT, PERIPLANETA AMERICANA L

The Journal of Cell Biology ◽

10.1083/jcb.29.3.449 ◽

1966 ◽

Vol 29 (3) ◽

pp. 449-459 ◽

Cited By ~ 39

Author(s):

David S. Smith

Keyword(s):

Periplaneta Americana ◽

Flight Muscle ◽

Muscle Fibers ◽

Structural Features ◽

Mitochondrial Content ◽

Thin Filaments ◽

Transverse Tubular System ◽

Thick Filaments ◽

Tubular System ◽

Contraction And Relaxation

The organization of intersegmental muscle fibers associated with the dorsal abdominal sclerites of the cockroach is described. These fibers correspond closely, in the disposition and derivation of the membranes of the transverse tubular system and sarcoplasmic reticulum cisternae, with insect synchronous flight muscle fibers, but differ markedly from these in their fibrillar architecture and mitochondrial content. The mitochondria are small and generally aligned alongside the prominent I bands of the sarcomere, and, in the best-oriented profiles of the A bands, thick filaments are associated with orbitals of twelve thin filaments, a configuration that has also been observed in striated fibers of insect visceral muscle. These structural features of insect muscles are compared and discussed in terms of possible variations in the control of contraction and relaxation, and in the nature of their mechanical role.

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The Structure of the Relaxed Thick Filaments from Lethocerus Asynchronous Flight Muscle

Biophysical Journal ◽

10.1016/j.bpj.2015.11.1616 ◽

2016 ◽

Vol 110 (3) ◽

pp. 300a

Author(s):

Zhongjun Hu ◽

Dianne W. Taylor ◽

Michael K. Reedy ◽

Robert J. Perz-Edwards ◽

kenneth A. Taylor

Keyword(s):

Flight Muscle ◽

Thick Filaments

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The Contributions of the Amino and Carboxy Terminal Domains of Flightin to the Biomechanical Properties of Drosophila Flight Muscle Thick Filaments

Biology ◽

10.3390/biology5020016 ◽

2016 ◽

Vol 5 (2) ◽

pp. 16 ◽

Cited By ~ 2

Author(s):

Nathan Gasek ◽

Lori Nyland ◽

Jim Vigoreaux

Keyword(s):

Flight Muscle ◽

Biomechanical Properties ◽

Thick Filaments ◽

Carboxy Terminal ◽

Terminal Domains

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THE FILAMENT LATTICE OF COCKROACH THORACIC MUSCLE

The Journal of Cell Biology ◽

10.1083/jcb.36.3.433 ◽

1968 ◽

Vol 36 (3) ◽

pp. 433-442 ◽

Cited By ~ 21

Author(s):

Martin Hagopian ◽

David Spiro

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Flight Muscle ◽

Insect Flight ◽

Thick Filament ◽

Leucophaea Maderae ◽

Thick Filaments ◽

Femoral Muscle ◽

Flight Muscles ◽

Characteristic 3

The fine structure of the tergo-coxal muscle of the cockroach, Leucophaea maderae, has been studied with the electron microscope. This muscle differs from some other types of insect flight muscles inasmuch as the ratio of thin to thick filaments is 4 instead of the characteristic 3. The cockroach flight muscle also differs from the cockroach femoral muscle in thin to thick filament ratios and diameters and in lengths of thick filaments. A comparison of these latter three parameters in a number of vertebrate and invertebrate muscles suggests in general that the diameters and lengths of the thick filaments and thin to thick filament ratios are related.

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