Division of Molecular Neurobiology, Rudolf Magnus Institute and Institute of Molecular biology. University of Utrecht, Utrecht (The Netherlands).
Restor Neurol Neurosci. 1990 Jan 1;1(3):237-44. doi: 10.3233/RNN-1990-13410.
The protein kinase C substrate B-50 is identical to the growth-associated protein GAP-43. Although as yet no causal relationship has been established between B-50/GAP-43 and neurite outgrowth, evidence accumulates that the function of the protein relates to neuronal plasticity. Stimulation of PC12 cells by NGF results in translocation of the protein from cytosolic stores to the membrane of newly formed neurite-like extensions. The protein is associated with the inner leaflet of the growth cone membrane isolated from neonatal rat brain and was used as a marker to study the development of the rat pyramidical tract and olfactory system. In the adult rat, crush lesion of the sciatic nerve results in a rapid expression of B-50/GAP-43 mRNA followed by synthesis of B-50/GAP-43 protein in dorsal root ganglia and transport of the protein into the newly formed sprouts. Presumably, the neurotrophic effect of melanocortins on peripheral nerve repair is not brought about by enhancement of B-50/GAP-43 synthesis per se. Bulbectomy (central) or Triton X-100 lesioning (peripheral) of the olfactory epithelium results in a differential expression of B-50/GAP-43 and the olfactory marker protein characterizing two stages in the regeneration of this epithelium. Evidence that the degree of phosphorylation may co-determine the role of B-50/GAP-43 in neurite outgrowth is discussed.
蛋白激酶 C 底物 B-50 与生长相关蛋白 GAP-43 相同。虽然迄今为止尚未建立 B-50/GAP-43 与轴突生长之间的因果关系，但有证据表明该蛋白的功能与神经元可塑性有关。NGF 刺激 PC12 细胞会导致该蛋白从细胞质库易位到新形成的类神经突延伸的膜上。该蛋白与从新生大鼠脑中分离的生长锥膜的内小叶相关联，并被用作标记物来研究大鼠锥体束和嗅觉系统的发育。在成年大鼠中，坐骨神经挤压损伤会导致 B-50/GAP-43 mRNA 的快速表达，随后在背根神经节中合成 B-50/GAP-43 蛋白，并将该蛋白转运到新形成的芽中。推测黑素皮质素对周围神经修复的神经营养作用不是通过增强 B-50/GAP-43 合成本身来实现的。球囊切除术（中枢）或 Triton X-100 损伤（外周）嗅上皮会导致 B-50/GAP-43 和嗅觉标记蛋白的差异表达，这是该上皮再生的两个阶段的特征。讨论了磷酸化程度可能共同决定 B-50/GAP-43 在轴突生长中的作用的证据。
