Biochemical and ultrastructural aspects of Mr 165,000 M-protein in cross-striated chicken muscle.

Strehler, Emanuel E.; Pelloni, G; Heizmann, Claus W.; Eppenberger, Hans M.

doi:10.1083/jcb.86.3.775

Cited by 36 publications

(24 citation statements)

References 42 publications

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“…This hypothesis is consistent with the perinatal replacement of the EH-splice variant by the more rigid myomesin 1 in heart (Agarkova et al, 2000). While myomesin may be an integral component of myofibrils even in the absence of a structurally visible M-line (Strehler et al, 1980), suggesting that EH-based myofilament linkages might be present in eye muscle, it is not yet clear what adaptive value EH-myomesin 1 may serve in a muscle that lacks the stereotypical structural connections between adjacent myosin filaments. Prior studies Eppenberger et al, 1981;Van der Ven et al, 1999;Yang et al, 2000) have shown that an M-line appears within H-zones of forming myofibrils and that myomesin 1 accumulation is coordinated with that of other myofibrillar proteins.…”

Section: Discussionsupporting

confidence: 49%

Postnatal suppression of myomesin, muscle creatine kinase and the M-line in rat extraocular muscle

Porter

Merriam

Gong

et al. 2003

Journal of Experimental Biology

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SUMMARYThe M-line and its associated creatine kinase (CK) M-isoform (CK-M) are ubiquitous features of skeletal and cardiac muscle. The M-line maintains myosin myofilaments in register, links the contractile apparatus to the cytoskeleton for external force transfer and localizes CK-based energy storage and transfer to the site of highest ATP demand. We establish here that the muscle group responsible for movements of the eye, extraocular muscle (EOM),is divergent from other striated muscles in lacking both an M-line and its associated CK-M. Although an M-line forms during myogenesis, both in vivo and in vitro, it is actively repressed after birth. Transcripts of the major M-line structural proteins, myomesin 1 and myomesin 2, follow the same pattern of postnatal downregulation, while the embryonic heart-specific EH-myomesin 1 transcript is expressed early and retained in adult eye muscle. By immunocytochemistry, myomesin protein is absent from adult EOM sarcomeres. M-line suppression does not occur in organotypic co-culture with oculomotor motoneurons, suggesting that the mechanism for suppression may lie in muscle group-specific activation or workload patterns experienced only in vivo. The M-line is, however, still lost in dark-reared rats, despite the developmental delay this paradigm produces in the visuomotor system and EOMs. EOM was low in all CK isoform transcripts except for the sarcomeric mitochondrial (Ckmt2) isoform. Total CK enzyme activity of EOM was one-third that of hindlimb muscle. These findings are singularly unique among fast-twitch skeletal muscles. Since EOM exhibits isoform diversity for other sarcomeric proteins, the M-line/CK-M divergence probably represents a key physiological adaptation for the unique energetics and functional demands placed on this muscle group in voluntary and reflexive eye movements.

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Section: Discussionsupporting

confidence: 49%

Postnatal suppression of myomesin, muscle creatine kinase and the M-line in rat extraocular muscle

Porter

Merriam

Gong

et al. 2003

Journal of Experimental Biology

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“…The M-line traverses the center of the A-band and consists of several M-bridges connecting adjacent thick filaments [Luther and Squire, 1978]. Biochemically, three proteins, MM-creatine kinase (43 kD), M-protein (165 kD) and myomesin (185 kD or 190 kD in skeletal muscle or cardiac muscle, respectively) have been identified [Strehler et al, , 1980Grove et al, 1984Grove et al, , 1985. Myomesin is expressed later than ␣-actinin and titin in cultured chicken skeletal myotubes [Lin et al, 1994], but appears at the same time as titin in human fetal skeletal muscle in which the incorporation of M-protein in striated myofibrils occurs later than myomesin [van der Ven and Fü rst, 1997].…”

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confidence: 99%

Role of M-line proteins in sarcomeric titin assembly during cardiac myofibrillogenesis

Wang

Shang

et al. 1998

J. Cell. Biochem.

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A rat polyclonal anti-M-line protein antiserum and three mouse monoclonal anti-titin antibodies (E2, F3, and A12) were used to study the spatiotemporal relationship between M-line proteins and titin during myofibril assembly in cultured chicken cardiomyocytes by immunofluorescence microscopy. In day 2 cultures, M-line proteins and titin were detected as punctate staining in most cardiomyocytes, which possessed many nonstriated fibrils. At a late stage (day 3 cultures), M-line proteins were incorporated into dot-like structures along nonstriated fibrils, while titin staining was continuous on these structures. As development progressed, M-line proteins were registered in periodic pattern in the mid-A band. In cardiomyocytes from day 5 cultures, the titin bands were separated by an unstained region, and achieved their adult doublet pattern. Thus, the organization of titin in the sarcomere appears to occur later than that of M-line proteins in the M-line. Our morphological data indicate that the early registration of M-line proteins in primitive myofibrils may guide titin filament alignment via interaction between M-line proteins and titin. In order to investigate the role of M-line proteins in the assembly of titin filaments, anti-M-line protein or anti-titin antibodies were introduced into cultured cardiomyocytes by electroporation to functionally bind the respective proteins, and the profile of myofibril assembly was examined. Cardiomyocytes from day 2-3 cultures with incorporated anti-M-line protein antibodies became shrunk, and exhibited defective myofibrillar assembly, as shown by the failure of titin to assemble into a typical sarcomeric pattern. Incorporation of anti-titin antibody E2, which recognizes the M-line end domain of titin, resulted in the failure of M-line proteins organized into the M-line structure, as shown by random, sporadic staining with anti-M-line protein antibody. These studies confirm the essential role of M-line proteins in the organization of titin filaments in the sarcomere and that the interaction between titin and M-line proteins is crucial to the formation of the M-line structure.

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“…It is, in fact, of considerable significance, since much of the present biochemical work on characterizing the M-band proteins appears to assume an M-band structure common to all vertebrate muscles. The cryo-sectioning studies which have now been carried out at our laboratories on many different muscles and fibre types from humans, rabbits, chickens, rats, frogs and fish should help to relate the recent plethora of biochemical studies (Trinick & Lowey, 1977;Dhanarajan & Atkinson, 1980;Mani et al, 1980;Strehler et al, 1980) to the specific M-band structure (or structures) known to be present in the particular muscles involved. It is a mistake to assume that A-band structure in all vertebrate muscles is the same.…”

Section: Cryo-sections and Vertebrate Muscle Researchmentioning

confidence: 99%

Muscle structure, cryo‐methods and image analysis

Squire

Edman

Freundlich

et al. 1982

Journal of Microscopy

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Negatively stained cryo-sections from glutaraldehyde fixed, anti-freeze treated muscle, quench-frozen in Freon cooled by liquid nitrogen, show improved preservation of the axial structure of the myofibrils compared with conventional plastic sections. Such sections are being used both to characterize the structural differences in the M-bands of different vertebrate muscles and fibre types and also to define the axial distribution of myosin crossbridges and nonmyosin proteins in the crossbridge region of the A-band. Combined with analysis of the transverse A-band structure from plastic sections, the cryo-sections are helping to reconstruct a three-dimensional picture of the molecular architecture of the A-band. This, in turn, is providing the necessary structural background with which to interpret the wealth of published X-ray diffraction data on muscle. Such data should reveal the nature of the contractile event itself.Since good X-ray diffraction patterns can be obtained from living muscles, these can be compared with optical diffraction patterns from muscle cryo-sections as a means of testing the degree of preservation in the sections. Muscle is therefore an excellent tissue with which to evaluate new cryo-techniques.

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Biochemical and ultrastructural aspects of Mr 165,000 M-protein in cross-striated chicken muscle.

Cited by 36 publications

References 42 publications

Postnatal suppression of myomesin, muscle creatine kinase and the M-line in rat extraocular muscle

Postnatal suppression of myomesin, muscle creatine kinase and the M-line in rat extraocular muscle

Role of M-line proteins in sarcomeric titin assembly during cardiac myofibrillogenesis

Muscle structure, cryo‐methods and image analysis

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