Suidan H S, Niclou S P, Dreessen J, Beltraminelli N, Monard D
Friedrich Miescher-Institut, CH-4002 Basel, Switzerland.
J Biol Chem. 1996 Nov 15;271(46):29162-9. doi: 10.1074/jbc.271.46.29162.
Cultured myoblasts derived from limb muscle of newborn rats express thrombin receptor immunoreactivity on their surface. Receptor expression is repressed upon myoblast fusion. This is due at least in part to a decrease in the amount of the thrombin receptor mRNA. Addition of thrombin triggers calcium transients only in mono- but not multinucleated muscle cells. Furthermore, thrombin increases the rate of myoblast proliferation that coincides with an activation of mitogen-activated protein kinase. Northern analysis of thrombin receptor mRNA expression in skeletal muscle showed that the transcript is present at a relatively high level at birth, but is almost undetectable in the adult. By in situ hybridization, the mRNA at birth appeared to be present mostly in mononucleated cells grouped in clusters, but not in muscle fibers. Very few nuclei surrounded by a mRNA signal were present on muscle sections of rats 24 days postnatally. These results suggest that the thrombin receptor plays a role in muscle development.
源自新生大鼠肢体肌肉的培养成肌细胞在其表面表达凝血酶受体免疫反应性。成肌细胞融合后受体表达受到抑制。这至少部分是由于凝血酶受体mRNA量的减少。添加凝血酶仅在单核而非多核肌肉细胞中引发钙瞬变。此外，凝血酶增加成肌细胞增殖速率，这与丝裂原活化蛋白激酶的激活相吻合。对骨骼肌中凝血酶受体mRNA表达的Northern分析表明，该转录本在出生时以相对较高的水平存在，但在成年动物中几乎检测不到。通过原位杂交，出生时的mRNA似乎主要存在于成簇的单核细胞中，而不存在于肌纤维中。出生后24天的大鼠肌肉切片上，很少有被mRNA信号包围的细胞核。这些结果表明凝血酶受体在肌肉发育中起作用。
