論文

国際誌
2022年6月27日

Endogenous slow and fast myosin dynamics in myofibers isolated from mice expressing GFP-Myh7 and Kusabira Orange-Myh1.

American journal of physiology. Cell physiology
  • Koichi Ojima
  • ,
  • Masahiro Kigaki
  • ,
  • Emi Ichimura
  • ,
  • Takahiro Suzuki
  • ,
  • Ken Kobayashi
  • ,
  • Susumu Muroya
  • ,
  • Takanori Nishimura

323
2
開始ページ
C520-C535
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1152/ajpcell.00415.2021

Skeletal muscle consists of slow and fast myofibers in which different myosin isoforms are expressed. Approximately 300 myosins form a single thick filament in the myofibrils, where myosin is continuously exchanged. However, endogenous slow and fast myosin dynamics have not been fully understood. To elucidate those dynamics, here we generated mice expressing green fluorescence protein-tagged slow myosin heavy chain (GFP-Myh7) and Kusabira Orange fluorescence protein-tagged fast myosin heavy chain (KuO-Myh1). First, these mice enabled us to distinguish between GFP- and KuO-myofibers under fluorescence microscopy: GFP-Myh7 and KuO-Myh1 were exclusively expressed in slow myofibers and fast myofibers, respectively. Next, to monitor endogenous myosin dynamics, fluorescence recovery after photobleaching (FRAP) was conducted. The mobile fraction (Mf) of GFP-Myh7 and that of KuO-Myh1 were almost constant values independent of the regions of the myofibers and the muscle portions where the myofibers were isolated. Intriguingly, proteasome inhibitor treatment significantly decreased the Mf in GFP-Myh7 but not in KuO-Myh1 myofibers, indicating that the response to a disturbance in protein turnover depended on muscle fiber type. Taken together, the present results indicated that the mice we generated are promising tools not only for distinguishing between GFP- and KuO-myofibers but also for studying the dynamics of endogenous myosin isoforms by live-cell fluorescence imaging.

リンク情報
DOI
https://doi.org/10.1152/ajpcell.00415.2021
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/35759444
ID情報
  • DOI : 10.1152/ajpcell.00415.2021
  • PubMed ID : 35759444

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