N-CAM at the vertebrate neuromuscular junction.
N-CAM at the vertebrate neuromuscular junction.
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DOI：
10.1083/jcb.101.1.285
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发表时间：
1985-07
期刊：
影响因子：
--
通讯作者：
Edelman GM
中科院分区：
文献类型：
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作者：
Rieger F;Grumet M;Edelman GM
我们已经检测到神经细胞粘附分子，N-CAM，在神经肌肉接触的发展和成年小鼠膈肌。虽然我们发现N-CAM染色与荧光抗体一致重叠的α-银环蛇毒素染色在神经-肌肉接触过程中，在发展和成人，我们观察到N-CAM染色的表面上的发展中的肌纤维和在成人肌纤维在低得多的水平。与其功能一致，N-CAM也在轴突和轴突终末检测到。用抗N-CAM抗体对胚胎（E）膈肌的洗涤剂提取物进行免疫印迹实验，结果显示多分散的多唾液酸化N-CAM多肽，在成人（A）中转化为Mr为140，000的离散形式;这种变化称为E-to-A转化，以前发现以不同的速率发生在不同的神经组织中。Mr 140，000组分不被单克隆抗体抗N-CAM No.5识别，其特异性识别与来自神经组织的N-CAM上的N-连接寡糖决定簇相关的抗原决定簇。从膈肌制备的Mr 140，000组分的相对浓度在胎儿发育期间增加，然后急剧下降，达到成人值。然而，N-CAM在肌肉中的表达可以诱导后去神经：坐骨神经切断后一周，N-CAM的相对量显着增加，通过免疫印迹检测的整个肌肉提取物。免疫荧光染色证实，有增加N-CAM，无论是在细胞和细胞表面，然而，在同一时间，在运动终板染色减少。我们的研究结果表明，在肌肉中，除了化学调制，N-CAM的细胞表面调制发生在胚胎发育过程中的数量和分布，并在响应去神经支配。
We have detected the neural cell adhesion molecule, N-CAM, at nerve- muscle contacts in the developing and adult mouse diaphragm. Whereas we found N-CAM staining with fluorescent antibodies consistently to overlap with the pattern of alpha-bungarotoxin staining at nerve-muscle contacts both during development and in the adult, we observed N-CAM staining on the surfaces of developing myofibers and at much lower levels on adult myofibers. Consistent with its function, N-CAM was also detected on axons and axon terminals. Immunoblotting experiments with anti-N-CAM antibodies on detergent extracts of embryonic (E) diaphragm muscle revealed a polydisperse polysialylated N-CAM polypeptide, which in the adult (A) was converted to a discrete form of Mr 140,000; this change, called E-to-A conversion, was previously found to occur in different neural tissues at different rates. The Mr 140,000 component was not recognized by monoclonal antibody anti-N-CAM No. 5, which specifically recognizes antigenic determinants associated with N-linked oligosaccharide determinants on N-CAM from neural tissue. The relative concentration of the Mr 140,000 component prepared from diaphragm muscle increased during fetal development and then decreased sharply to reach adult values. Nevertheless, expression of N-CAM in muscle could be induced after denervation: one week after the sciatic nerve was severed, the relative amount of N-CAM increased dramatically as detected by immunoblots of extracts of whole muscle. Immunofluorescent staining confirmed that there was an increase in N-CAM, both in the cell and at the cell surface; at the same time, however, staining at the motor endplate was diminished. Our findings indicate that, in muscle, in addition to chemical modulation, cell-surface modulation of N-CAM occurs both in amount and distribution during embryogenesis and in response to denervation.