LaRochelle W J, Witzemann V, Fiedler W, Froehner S C
Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03756.
J Neurosci. 1990 Oct;10(10):3460-7. doi: 10.1523/JNEUROSCI.10-10-03460.1990.
The expression of the postsynaptic 43-kDa and 58-kDa proteins and actin during development of the Torpedo marmorata electric organ was compared to that of nicotinic acetylcholine receptors (AChRs). Western blot analysis demonstrates that AChRs and proteins of 43 kDa (43K protein) and 58 kDa (58K protein) are all present prior to synaptogenesis. Subsequently, levels of all 3 synaptic proteins increase dramatically during differentiation and innervation of electrocytes. In contrast, actin is present in relatively high concentrations at early times and decreases thereafter. The equimolar ratio of AChRs and the 43K protein found in the adult electric organ is established early in development. Furthermore, the AChR and 43K protein share a common postsynaptic localization in electrocytes following synapse formation. Aggregates of the AChR that form at the ventral pole of the oval-shaped electrocytes prior to innervation, however, show no detectable immunofluorescence staining with anti-43K monoclonal antibodies. Therefore, in some cases, aggregation of AChRs occurs without the 43K protein.
将电鳐电器官发育过程中突触后43 kDa和58 kDa蛋白及肌动蛋白的表达与烟碱型乙酰胆碱受体（AChRs）的表达进行了比较。蛋白质印迹分析表明，在突触形成之前，AChRs以及43 kDa（43K蛋白）和58 kDa（58K蛋白）的蛋白质均已存在。随后，在电细胞分化和神经支配过程中，所有这3种突触蛋白的水平都急剧增加。相比之下，肌动蛋白在早期以相对较高的浓度存在，此后则下降。成体电器官中发现的AChRs与43K蛋白的等摩尔比在发育早期就已确立。此外，在突触形成后，AChR和43K蛋白在电细胞中共享一个共同的突触后定位。然而，在神经支配之前在椭圆形电细胞腹极形成的AChR聚集体，用抗43K单克隆抗体未检测到免疫荧光染色。因此，在某些情况下，AChRs的聚集在没有43K蛋白的情况下发生。
