Journal article

Cytoskeletal Tropomyosin Tm5NM1 Is Required for Normal Excitation-Contraction Coupling in Skeletal Muscle

Nicole Vlahovich, Anthony J Kee, Chris Van der Poel, Emma Kettle, Delia Hernandez-Deviez, Christine Lucas, Gordon S Lynch, Robert G Parton, Peter W Gunning, Edna C Hardeman



The functional diversity of the actin microfilaments relies in part on the actin binding protein tropomyosin (Tm). The muscle-specific Tms regulate actin-myosin interactions and hence contraction. However, there is less known about the roles of the numerous cytoskeletal isoforms. We have shown previously that a cytoskeletal Tm, Tm5NM1, defines a Z-line adjacent cytoskeleton in skeletal muscle. Recently, we identified a second cytoskeletal Tm in this region, Tm4. Here we show that Tm4 and Tm5NM1 define separate actin filaments; the former associated with the terminal sarcoplasmic reticulum (SR) and other tubulovesicular structures. In skeletal muscles of Tm5NM1 knockout (KO) mice, Tm4 localiz..

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University of Melbourne Researchers


Awarded by Australian National and Medical Research Council ( NHMRC)

Awarded by NHMRC

Funding Acknowledgements

We thank the staff of the Electron Microscope Laboratory ( a joint facility of the Institute of Clinical Pathology and Medical Research and the Westmead Research Hub), especially Ross Boadle for expert advice with immunolabeling techniques. This work was supported by Australian National and Medical Research Council ( NHMRC) grants 321705 ( to P. W. G., E. C. H., and A. J. K.) and 511005 ( to R. G. P.) and by funding from the Oncology Children's Foundation ( to P. W. G.). P. W. G. and R. G. P. are Principal Research Fellows of the NHMRC ( grant 163626 and 351411, respectively).