O-GlcNAcylation of tubulin inhibits its polymerization
O-GlcNAcylation of tubulin inhibits its polymerization
复制标题
DOI：
10.1007/s00726-010-0698-9
复制
发表时间：
2011-03-01
期刊：
影响因子：
3.5
通讯作者：
Cho, Jin Won
中科院分区：
文献类型：
--
作者：
Ji, Suena;Kang, Jeong Gu;Cho, Jin Won
O-连接的β-N-乙酰葡糖胺（O-GlcNAc）与蛋白质的连接是一种丰富且可逆的修饰，其涉及许多细胞过程，包括转录、翻译、细胞增殖、凋亡和信号转导。在这里，我们发现，O-GlcNAc的修改模式改变全反式维甲酸（tRA）诱导的神经突起生长在MN 9D神经元细胞系。我们使用质谱分析鉴定了几种O-GlcNAc酰化蛋白，包括α-和β-微管蛋白。α-和β-微管蛋白的进一步分析显示，O-GlcNAc酰化肽分别定位在α-微管蛋白的残基173和185之间以及β-微管蛋白的残基216和238之间。我们发现α-微管蛋白O-GlcNAc酰化的增加减少了异源二聚化，并且O-GlcNAc酰化的微管蛋白不进入微管。因此，当O-GlcNAcase抑制剂与tRA共孵育时，与对照相比，神经突生长的程度降低了20%。因此，我们的数据表明，微管蛋白的O-GlcNAc酰化负调控微管的形成。
The attachment of O-linked beta-N-acetylglucosamine (O-GlcNAc) to proteins is an abundant and reversible modification that involves many cellular processes including transcription, translation, cell proliferation, apoptosis, and signal transduction. Here, we found that the O-GlcNAc modification pattern was altered during all-trans retinoic acid (tRA)-induced neurite outgrowth in the MN9D neuronal cell line. We identified several O-GlcNAcylated proteins using mass spectrometric analysis, including alpha- and beta-tubulin. Further analysis of alpha- and beta-tubulin revealed that O-GlcNAcylated peptides mapped between residues 173 and 185 of alpha-tubulin and between residues 216 and 238 of beta-tubulin, respectively. We found that an increase in alpha-tubulin O-GlcNAcylation reduced heterodimerization and that O-GlcNAcylated tubulin did not polymerize into microtubules. Consequently, when O-GlcNAcase inhibitors were co-incubated with tRA, the extent of neurite outgrowth was decreased by 20% compared to control. Thus, our data indicate that the O-GlcNAcylation of tubulin negatively regulates microtubule formation.