Role of stress fiber-like structures in assembling nascent myofibrils in myosheets recovering from exposure to ethyl methanesulfonate

doi:10.1083/jcb.102.4.1464

This Article

	Full Text (PDF, 2922K)
	Alert me when this article is cited
	Citation Map

Services

	Email this article
	Similar articles in this journal
	Similar articles in PubMed
	Alert me to new content in the JCB
	Download to citation manager

Citing Articles

	Citing Articles via HighWire
	Citing Articles via CrossRef
	Citing Articles via Google Scholar

Google Scholar

	Articles by Antin, P. B.
	Articles by Holtzer, H.
	Search for Related Content

PubMed

	PubMed Citation
	Articles by Antin, P. B.
	Articles by Holtzer, H.


Social Bookmarking

	What's this?

ARTICLES

Role of stress fiber-like structures in assembling nascent myofibrils in myosheets recovering from exposure to ethyl methanesulfonate

PB Antin, S Tokunaka, VT Nachmias and H Holtzer

When day 1 cultures of chick myogenic cells were exposed to the mutagenic alkylating agent ethyl methanesulfonate (EMS) for 3 d, 80% of the replicating cells were killed, but postmitotic myoblasts survived. The myoblasts fused to form unusual multinucleated "myosheets": extraordinarily wide, flattened structures that were devoid of myofibrils but displayed extensive, submembranous stress fiber-like structures (SFLS). Immunoblots of the myosheets indicated that the carcinogen blocked the synthesis and accumulation of the myofibrillar myosin isoforms but not that of the cytoplasmic myosin isoform. When removed from EMS, widely spaced nascent myofibrils gradually emerged in the myosheets after 3 d. Striking co-localization of fluorescent reagents that stained SFLS and those that specifically stained myofibrils was observed for the next 2 d. By both immunofluorescence and electron microscopy, individual nascent myofibrils appeared to be part of, or juxtaposed to, preexisting individual SFLS. By day 6, all SFLS had disappeared, and the definitive myofibrils were displaced from their submembranous site into the interior of the myosheet. Immunoblots from recovering myosheets demonstrated a temporal correlation between the appearance of the myofibrillar myosin isoforms and the assembly of thick filaments. The assembly of definitive myofibrils did not appear to involve desmin intermediate filaments, but a striking aggregation of sarcoplasmic reticulum elements was seen at the level of each I-Z-band. Our findings suggest that SFLS in the EMS myosheets function as early, transitory assembly sites for nascent myofibrils.
Add to CiteULike CiteULike Add to Complore Complore Add to Connotea Connotea Add to Del.icio.us Del.icio.us Add to Digg Digg Facebook Add to Reddit Reddit Add to Technorati Technorati Twitter What's this?

This article has been cited by other articles:

Malek, A. M., Xu, C., Kim, E. S., Alper, S. L. (2007). Hypertonicity triggers RhoA-dependent assembly of myosin-containing striated polygonal actin networks in endothelial cells. Am. J. Physiol. Cell Physiol. 292: C1645-C1659 [Abstract] [Full Text]
Ojima, K., Lin, Z.X., Bang, M.-L., Holtzer, S., Matsuda, R., Labeit, S., Sweeney, H.L., Holtzer, H. (2000). Distinct Families of Z-Line Targeting Modules in the Cooh-Terminal Region of Nebulin. JCB 150: 553-566 [Abstract] [Full Text]
Ojima, K, Lin, Z., Zhang, Z., Hijikata, T, Holtzer, S, Labeit, S, Sweeney, H., Holtzer, H (1999). Initiation and maturation of I-Z-I bodies in the growth tips of transfected myotubes. J. Cell Sci. 112: 4101-4112 [Abstract]
Almenar-Queralt, A, Gregorio, C., Fowler, V. (1999). Tropomodulin assembles early in myofibrillogenesis in chick skeletal muscle: evidence that thin filaments rearrange to form striated myofibrils. J. Cell Sci. 112: 1111-1123 [Abstract]
Belkin, A. M., Burridge, K. (1994). Expression and localization of the phosphoglucomutase-related cytoskeletal protein, aciculin, in skeletal muscle. J. Cell Sci. 107: 1993-2003 [Abstract]