Lognonne J L, Wahrmann J P
U15 of the INSERM, 24, Paris, France.
Exp Cell Res. 1990 Mar;187(1):90-7. doi: 10.1016/0014-4827(90)90121-p.
During in vitro myogenesis, mononucleated myoblasts fuse among themselves to form multinucleated myotubes. We have recently reported for the first time in the literature that a Ca2(+)-dependent ectoprotein kinase is responsible for this process, but we had no direct evidence for the role of extracellular ATP. To investigate whether the cells can fuse or not in the absence of this nucleotide, we used a nucleotide affinity label, fluorosulfonylbenzoyl adenosine (FSBA). We report here its use in detecting the nucleotide-binding sites at the cell surface of intact myoblasts in culture. We demonstrate that FSBA blocks fusion by inhibiting the ectoprotein kinase activity of the cells at sublethal concentrations. Radioactive [14C]SBA is incorporated into seven cell surface proteins and into the 48-kDa protein, among others. This species is specific for fusion-competent myoblasts and is implicated in this process. This is the first time that nucleotide-binding molecular species have been identified at the surface of myoblasts.
在体外肌生成过程中，单核成肌细胞相互融合形成多核肌管。我们最近首次在文献中报道，一种Ca2+依赖性胞外蛋白激酶负责这一过程，但我们没有细胞外ATP作用的直接证据。为了研究在没有这种核苷酸的情况下细胞是否能够融合，我们使用了一种核苷酸亲和标记物，即氟磺酰苯甲酰腺苷（FSBA）。我们在此报告其在检测培养的完整成肌细胞表面核苷酸结合位点中的应用。我们证明，FSBA在亚致死浓度下通过抑制细胞的胞外蛋白激酶活性来阻断融合。放射性[14C]SBA被掺入七种细胞表面蛋白以及48 kDa蛋白等。该蛋白是有融合能力的成肌细胞所特有的，并且与这一过程有关。这是首次在成肌细胞表面鉴定出核苷酸结合分子种类。
