Details

Autor(en) / Beteiligte

• Millay, Douglas P.
• Gamage, Dilani G.
• Quinn, Malgorzata E.
• Min, Yi-Li
• Mitani, Yasuyuki
• Bassel-Duby, Rhonda
• Olson, Eric N.

Titel

Structure–function analysis of myomaker domains required for myoblast fusion

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2016-02, Vol.113 (8), p.2116-2121

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2016

Quelle

Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals

Beschreibungen/Notizen

• During skeletal muscle development, myoblasts fuse to form multinucleated myofibers. Myomaker [Transmembrane protein 8c (TMEM8c)] is a muscle-specific protein that is essential for myoblast fusion and sufficient to promote fusion of fibroblasts with muscle cells; however, the structure and biochemical properties of this membrane protein have not been explored. Here, we used CRISPR/Cas9 mutagenesis to disrupt myomaker expression in the C2C12 muscle cell line, which resulted in complete blockade to fusion. To define the functional domains of myomaker required to direct fusion, we established a heterologous cell–cell fusion system, in which fibroblasts expressing mutant versions of myomaker were mixed with WT myoblasts. Our data indicate that the majority of myomaker is embedded in the plasma membrane with seven membrane-spanning regions and a required intracellular C-terminal tail. We show that myomaker function is conserved in other mammalian orthologs; however, related family members (TMEM8a and TMEM8b) do not exhibit fusogenic activity. These findings represent an important step toward deciphering the cellular components and mechanisms that control myoblast fusion and muscle formation.