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
MOLECULAR BIOLOGY OF THE CELL | AMER SOC CELL BIOLOGY | Published : 2009
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..View full abstract
Awarded by Australian National and Medical Research Council ( NHMRC)
Awarded by NHMRC
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).