CAPN3 is a muscle-specific and an intrinsically disordered protein. Thus, as a scaffolding protein CAPN3 could play a role during early stages of myogenesis. To test this hypothesis, we studied the distribution and function of CAPN3 during myogenesis using embryonic chick muscle cells grown in vitro. Super-resolution microscopy showed CAPN3 distribution in (i) amorphous patches in myoblasts, (ii) a region near the nuclei of myotubes; (iii) adhesion plaques in myotubes, (iv) stress fiber-like structures in myotubes, and (v) filaments in fibroblasts. Downregulation of CAPN3 induced a decrease in the number of muscle cells and in the size of myotubes formed. These data show a diverse intracellular distribution of CAPN3, compatible with a scaffolding protein, and suggest a multitude of different interactions of CAPN3 with other partners during muscle formation.

CAPN3 是一种肌肉特异性和本质上无序的蛋白质。因此，作为支架蛋白 CAPN3 可以在肌生成的早期阶段发挥作用。为了验证这一假设，我们使用体外培养的雏鸡肌肉细胞研究了 CAPN3 在肌生成过程中的分布和功能. 超分辨率显微镜显示 CAPN3 分布在（i）成肌细胞中的无定形斑块，（ii）靠近肌管细胞核的区域；(iii) 肌管中的粘连斑块，(iv) 肌管中的应力纤维样结构，以及 (v) 成纤维细胞中的细丝。CAPN3 的下调诱导肌肉细胞数量和形成的肌管大小的减少。这些数据显示了 CAPN3 的多种细胞内分布，与支架蛋白兼容，并表明在肌肉形成过程中 CAPN3 与其他伙伴之间存在多种不同的相互作用。