Laboratory of Intracellular Signaling, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Sci Signal. 2011 Apr 26;4(170):ra26. doi: 10.1126/scisignal.2001127.
Semaphorin3A (Sema3A) is a repulsive guidance molecule for axons, which acts by inducing growth cone collapse through phosphorylation of CRMP2 (collapsin response mediator protein 2). Here, we show a role for CRMP2 oxidation and thioredoxin (TRX) in the regulation of CRMP2 phosphorylation and growth cone collapse. Sema3A stimulation generated hydrogen peroxide (H2O2) through MICAL (molecule interacting with CasL) and oxidized CRMP2, enabling it to form a disulfide-linked homodimer through cysteine-504. Oxidized CRMP2 then formed a transient disulfide-linked complex with TRX, which stimulated CRMP2 phosphorylation by glycogen synthase kinase-3, leading to growth cone collapse. We also reconstituted oxidation-dependent phosphorylation of CRMP2 in vitro, using a limited set of purified proteins. Our results not only clarify the importance of H2O2 and CRMP2 oxidation in Sema3A-induced growth cone collapse but also indicate an unappreciated role for TRX in linking CRMP2 oxidation to phosphorylation.
神经丝氨酸蛋白 3A（Sema3A）是一种轴突排斥性导向分子，通过磷酸化 CRMP2（坍塌反应调节蛋白 2）诱导生长锥塌陷。在这里，我们展示了 CRMP2 氧化和硫氧还蛋白（TRX）在调节 CRMP2 磷酸化和生长锥塌陷中的作用。Sema3A 刺激通过 MICAL（与 CasL 相互作用的分子）产生过氧化氢（H2O2），并氧化 CRMP2，使其能够通过半胱氨酸-504 形成二硫键连接的同源二聚体。然后，氧化的 CRMP2 与 TRX 形成瞬时二硫键连接的复合物，刺激糖原合酶激酶-3 磷酸化 CRMP2，导致生长锥塌陷。我们还使用有限的一组纯化蛋白在体外重建了 CRMP2 的氧化依赖性磷酸化。我们的研究结果不仅阐明了 H2O2 和 Sema3A 诱导的生长锥塌陷中 CRMP2 氧化的重要性，还表明了 TRX 在将 CRMP2 氧化与磷酸化联系起来方面的作用未被充分认识。
