The structure of the sarcomeric M band: localization of defined domains of myomesin, M-protein, and the 250-kD carboxy-terminal region of titin by immunoelectron microscopy - PubMed (original) (raw)
The structure of the sarcomeric M band: localization of defined domains of myomesin, M-protein, and the 250-kD carboxy-terminal region of titin by immunoelectron microscopy
W M Obermann et al. J Cell Biol. 1996 Sep.
Abstract
The M band of vertebrate cross-striated myofibrils has remained an enigmatic structure. In addition to myosin thick filaments, two major structural proteins, myomesin and M-protein, have been localized to the M band. Also, titin is expected to be anchored in this structure. To begin to understand the molecular layout of these three proteins, a panel of 16 polyclonal and monoclonal antibodies directed against unique epitopes of defined sequence was assembled, and immunoelectron microscopy was used to locate the position of the epitopes at the sarcomere level. The results allow the localization and orientation of defined domains of titin, myomesin, and M-protein at high resolution. The 250-kD carboxy-terminal region of titin clearly enters the M band with the kinase domain situated approximately 52 nm from the central M1-line. The positions of three additional epitopes are compatible with the view that the titin molecule reaches approximately 60 nm into the opposite sarcomere half. Myomesin also seems to bridge the central M1-line and is oriented parallel to the long axis of the myofibril. The neighboring molecules are oriented in an antiparallel and staggered fashion. The amino-terminal portion of the protein, known to contain a myosin binding site, seems to adopt a specific three-dimensional arrangement. While myomesin is present in both slow and fast fibers, M-protein is restricted to fast fibers. It appears to be organized in a fundamentally different manner: the central portion of the polypeptide is around the M1-line, while the terminal epitopes seem to be arranged along thick filaments. This orientation fits the conspicuously stronger M1-lines in fast twitch fibers. Obvious implications of this model are discussed.
Similar articles
- Assembly of titin, myomesin and M-protein into the sarcomeric M band in differentiating human skeletal muscle cells in vitro.
van der Ven PF, Fürst DO. van der Ven PF, et al. Cell Struct Funct. 1997 Feb;22(1):163-71. doi: 10.1247/csf.22.163. Cell Struct Funct. 1997. PMID: 9113403 - Myomesin 3, a novel structural component of the M-band in striated muscle.
Schoenauer R, Lange S, Hirschy A, Ehler E, Perriard JC, Agarkova I. Schoenauer R, et al. J Mol Biol. 2008 Feb 15;376(2):338-51. doi: 10.1016/j.jmb.2007.11.048. Epub 2007 Nov 22. J Mol Biol. 2008. PMID: 18177667 - The M-band: an elastic web that crosslinks thick filaments in the center of the sarcomere.
Agarkova I, Perriard JC. Agarkova I, et al. Trends Cell Biol. 2005 Sep;15(9):477-85. doi: 10.1016/j.tcb.2005.07.001. Trends Cell Biol. 2005. PMID: 16061384 Review. - The role of the M-band myomesin proteins in muscle integrity and cardiac disease.
Lamber EP, Guicheney P, Pinotsis N. Lamber EP, et al. J Biomed Sci. 2022 Mar 7;29(1):18. doi: 10.1186/s12929-022-00801-6. J Biomed Sci. 2022. PMID: 35255917 Free PMC article. Review.
Cited by
- Dynamic Alterations to α-Actinin Accompanying Sarcomere Disassembly and Reassembly during Cardiomyocyte Mitosis.
Fan X, Hughes BG, Ali MA, Cho WJ, Lopez W, Schulz R. Fan X, et al. PLoS One. 2015 Jun 15;10(6):e0129176. doi: 10.1371/journal.pone.0129176. eCollection 2015. PLoS One. 2015. PMID: 26076379 Free PMC article. - The zebrafish runzel muscular dystrophy is linked to the titin gene.
Steffen LS, Guyon JR, Vogel ED, Howell MH, Zhou Y, Weber GJ, Zon LI, Kunkel LM. Steffen LS, et al. Dev Biol. 2007 Sep 15;309(2):180-92. doi: 10.1016/j.ydbio.2007.06.015. Epub 2007 Jun 23. Dev Biol. 2007. PMID: 17678642 Free PMC article. - Muscle-specific RING finger-1 interacts with titin to regulate sarcomeric M-line and thick filament structure and may have nuclear functions via its interaction with glucocorticoid modulatory element binding protein-1.
McElhinny AS, Kakinuma K, Sorimachi H, Labeit S, Gregorio CC. McElhinny AS, et al. J Cell Biol. 2002 Apr 1;157(1):125-36. doi: 10.1083/jcb.200108089. Epub 2002 Apr 1. J Cell Biol. 2002. PMID: 11927605 Free PMC article. - The NH2 terminus of titin spans the Z-disc: its interaction with a novel 19-kD ligand (T-cap) is required for sarcomeric integrity.
Gregorio CC, Trombitás K, Centner T, Kolmerer B, Stier G, Kunke K, Suzuki K, Obermayr F, Herrmann B, Granzier H, Sorimachi H, Labeit S. Gregorio CC, et al. J Cell Biol. 1998 Nov 16;143(4):1013-27. doi: 10.1083/jcb.143.4.1013. J Cell Biol. 1998. PMID: 9817758 Free PMC article. - A map of the phosphoproteomic alterations that occur after a bout of maximal-intensity contractions.
Potts GK, McNally RM, Blanco R, You JS, Hebert AS, Westphall MS, Coon JJ, Hornberger TA. Potts GK, et al. J Physiol. 2017 Aug 1;595(15):5209-5226. doi: 10.1113/JP273904. Epub 2017 Jul 4. J Physiol. 2017. PMID: 28542873 Free PMC article.
References
- J Muscle Res Cell Motil. 1994 Dec;15(6):633-45 - PubMed
- Structure. 1995 Apr 15;3(4):391-401 - PubMed
- J Mol Cell Cardiol. 1995 Apr;27(4):951-9 - PubMed
- Science. 1995 Oct 13;270(5234):293-6 - PubMed
- Eur J Biochem. 1995 Oct 1;233(1):110-5 - PubMed