Structural characterization by tandem mass spectrometry of the posttranslational polyglycylation of tubulin.
Structural characterization by tandem mass spectrometry of the posttranslational polyglycylation of tubulin.
复制标题
通过串联质谱法对微管蛋白翻译后多糖基化进行结构表征。
DOI：
10.1021/bi982304s
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发表时间：
1999
期刊：
影响因子：
2.9
通讯作者：
Jean Rossier
中科院分区：
文献类型：
--
作者：
Joëlle Vinh;James I. Langridge;M. Bré;N. Levilliers;V. Redeker;Denis Loyaux;Jean Rossier
Polyglycylation is a posttranslational modification specific to tubulin. This modification was originally identified in highly stable microtubules from Paramecium cilia. As many as 34 posttranslationally added glycine residues have been located in the C-terminal domains of Paramecium alpha- and beta-tubulin. In this study, post source decay matrix-assisted laser desorption/ionization mass spectrometry (PSD MALDI MS) and electrospray ionization on a hybrid quadrupole orthogonal time-of-flight tandem mass spectrometer (ESI Q-TOF MS/MS) were both used to demonstrate that a single molecule of beta-tubulin, from either dynamic cytoplasmic microtubules or stable axonemal microtubules, can be glycylated on each of the last four C-terminal glutamate residues Glu437, Glu438, Glu439, and Glu441 in the sequence 427DATAEEEGEFEEEGEQ442. In both dynamic and stable microtubules the most abundant beta-tubulin isoform contains six posttranslationally added glycine residues: two glycine residues on both Glu437 and Glu438 and one glycine residue on both Glu439 and Glu441. The number and relative abundance of glycylated isoforms of beta-tubulin in both cytoplasmic and axonemal microtubules were compared by MALDI MS.1 The abundance of the major glycylated isoforms in axonemal tubulin decreases regularly with glycylation levels from 6 to 19 whereas it drops abruptly in cytoplasmic tubulin with glycylation levels from 6 to 9. However, the polyglycine chains are similarly distributed on the four C-terminal glutamate residues of cytoplasmic and axonemal tubulin. The polyglycylation results in bulky C-terminal domains with negatively charged surfaces, all surrounding the microtubular structure.
