α1A and α1C form microtubules to display distinct properties mainly mediated by their C-terminal tails  

作　　者：Lei Diao Ming-Yi Liu Yin-Long Song Xu Zhang Xin Liang Lan Bao 

机构地区：[1]State Key Laboratory of Cell Biology,Shanghai Institute of Biochemistry and Cell Biology,Center for Excellence in Molecular Cell Science,University of Chinese Academy of Sciences,Chinese Academy of Sciences,Shanghai 200031,China [2]School of Life Science and Technology,ShanghaiTech University,Shanghai 201210,China [3]Tsinghua-Peking Joint Center for Life Sciences,School of Life Sciences,Tsinghua University,Beijing 100084,China [4]Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China

出　　处：《Journal of Molecular Cell Biology》2021年第12期864-875,共12页分子细胞生物学报（英文版）

基　　金：This work was supported by grants from the National Natural Science Foundation of China(31991194,31330046,and 31922018);the Strategic Priority Research Program of Chinese Academy of Sciences(XDB19000000).

摘　　要：Microtubules consisting of a/b-tubulin dimers play critical roles in cells.More than seven genes encode a-tubulin in vertebrates.However,the property of microtubules composed of different a-tubulin isotypes is largely unknown.Here,we purified recombinant tubulin heterodimers of mouse a-tubulin isotypes including a1A and a1C with b-tubulin isotype b2A.In vitro microtubule reconstitution assay detected that a1C/b2A microtubules grew faster and underwent catastrophe less frequently than a1A/b2A microtubules.Generation of chimeric tail-swapped and point-mutation tubulins revealed that the carboxyl-terminal(C-terminal)tails of a-tubulin isotypes largely accounted for the differences in polymerization dynamics of a1A/b2A and a1C/b2A microtubules.Kinetics analysis showed that in comparison to a1A/b2A microtubules,a1C/b2A microtubules displayed higher on-rate,lower off-rate,and similar GTP hydrolysis rate at the plus-end,suggesting a contribution of higher plus-end affinity to faster growth and less frequent catastrophe of a1C/b2A microtubules.Furthermore,EB1 had a higher binding ability to a1C/b2A microtubules than to a1A/b2A ones,which could also be attributed to the difference in the C-terminal tails of these two a-tubulin isotypes.Thus,a-tubulin isotypes diversify microtubule properties,which,to a great extent,could be accounted by their C-terminal tails.

关 键 词：α-tubulin isotype microtubule dynamics TIRF 

分 类 号：Q25[生物学—细胞生物学]