Developmental Biology Unit, UCL Institute of Child Health, London, United Kingdom.
Dev Neurobiol. 2010 May;70(6):456-71. doi: 10.1002/dneu.20789.
It is becoming apparent that regulation at the protein level plays crucial roles in developmental and pathological processes. Therefore, we performed a proteomics screen to identify proteins that are differently expressed or modified at stages of development permissive (E11) and nonpermissive for regeneration (E15) of the chick spinal cord. Proteins regulated either developmentally or in response to spinal-cord injury included collapsin-response-mediator proteins (Crmps), known to modulate microtubule dynamic and axonal growth. No significant changes in Crmp transcripts following injury were observed, indicating regulation mainly at the protein level. Analysis of Crmp-2 protein and its phosphorylated forms, pS522 and pT514, showed that Crmp-2 is developmentally regulated and also expressed in neural progenitors in vivo and in neurospheres. Its cellular localization changed both with development and following spinal-cord injury. In addition, although overall levels of Crmp-2 expression were not affected by injury, abundance of certain phosphorylated forms was altered. pT514 Crmp-2 appeared to be associated with dividing neural progenitors and was greatly reduced at nonpermissive stages for regeneration, whereas it did not seem affected by injury. In contrast, phosphorylation of Crmp-2 at S522 was upregulated early after injury in regenerating spinal cords and the ratio between phosphorylated to total Crmp-2 increased, as indicated by 2D Western blots. Altogether, this study shows highly dynamic regulation of Crmp-2 forms during development and identifies post-translational changes in Crmp-2 as putative contributors to the maintenance of spinal-cord regenerative ability, possibly via a transient stabilization of the neuronal cytoskeleton.
很明显，蛋白质水平的调控在发育和病理过程中起着至关重要的作用。因此，我们进行了蛋白质组学筛选，以鉴定在小鸡脊髓发育允许（E11）和非允许（E15）阶段表达或修饰不同的蛋白质。受发育调控或对脊髓损伤有反应的蛋白质包括 collapsin-响应-介体蛋白（Crmps），已知其调节微管动态和轴突生长。损伤后未观察到 Crmp 转录本的显著变化，表明主要在蛋白质水平上进行调节。Crmp-2 蛋白及其磷酸化形式 pS522 和 pT514 的分析表明，Crmp-2 受发育调控，并且在体内和神经球中也表达于神经祖细胞。其细胞定位在发育过程中和脊髓损伤后均发生变化。此外，尽管损伤没有影响 Crmp-2 的总体表达水平，但某些磷酸化形式的丰度发生了改变。pT514 Crmp-2 似乎与分裂的神经祖细胞有关，在再生非允许阶段大量减少，而似乎不受损伤影响。相比之下，Crmp-2 在 S522 的磷酸化在损伤后再生的脊髓中早期上调，并且磷酸化的 Crmp-2 与总 Crmp-2 的比例增加，如 2D Western blot 所示。总的来说，这项研究表明 Crmp-2 形式在发育过程中具有高度动态的调节，并确定了 Crmp-2 的翻译后变化可能是维持脊髓再生能力的潜在贡献因素，可能通过神经元细胞骨架的短暂稳定。
