The A and B tubules of the outer doublers of sea urchin sperm axonemes are composed of different tubulin variants
The A and B tubules of the outer doublers of sea urchin sperm axonemes are composed of different tubulin variants
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DOI：
10.1021/bi961057u
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发表时间：
1996-08-20
期刊：
影响因子：
2.9
通讯作者：
Weber, K
中科院分区：
文献类型：
--
作者：
Multigner, L;PignotPaintrand, I;Weber, K
微管蛋白的结构单位α β-微管蛋白异源二聚体有许多变体，存在由多基因家族编码的不同的α和β同种型，另外的异质性由一组翻译后修饰产生，α-微管蛋白的去酪氨酸化，α-微管蛋白的羧基末端Glu-Tyr二肽的去除，一些微管蛋白的磷酸化，多聚谷氨酰化，α-和β-微管蛋白的多聚甘氨酰化都涉及酸性羧基末端区域。我们通过免疫学方法和羧基末端肽的直接测序和质谱分析，包含9个外倍增体的A和B小管在微管蛋白变体方面有很大不同。A小管含有超过95%的未修饰的酪氨酸化α β-微管蛋白。在B小管中，α-微管蛋白类似于65%的去酪氨酸化，α-和β-微管蛋白均为40 - 45%的多聚甘氨酰化。这些结果显示了微管蛋白变体在两种不同轴丝结构之间的分离，并提高了微管蛋白的翻译后修饰反映或指定结构和功能不同微管的可能性。
The alpha beta-tubulin heterodimer, the structural unit of microtubules, comes in many variants, There are different alpha and beta isotypes encoded by multigene families, Additional heterogeneity is generated by a set of posttranslational modifications, Detyrosination of alpha-tubulin, removal of the carboxy-terminal Glu-Tyr dipeptide of alpha-tubulin, phosphorylation of some tubulins, polyglutamylation, and polyglycylation of alpha- and beta-tubulins all involve the acidic carboxy-terminal region, We have investigated the distribution of tubulin variants in the axonemal microtubules of sea urchin sperm flagella by immunological procedures and by direct sequence and mass spectrometric analysis of the carboxy-terminal peptides, The A and B tubules that comprise the nine outer doublers differ strongly in tubulin variants, A tubules contain over 95% unmodified, tyrosinated alpha beta-tubulin. In B tubules, alpha-tubulin is similar to 65% detyrosinated and both alpha-and beta-tubulin are 40-45% polyglycylated, These results show a segregation of tubulin variants between two different axonemal structures and raise the possibility that posttranslational modifications of tubulins reflect or specify structurally and functionally distinct microtubules.