Alp7-Mto1 and Alp 14 synergize to promote interphase microtubule regrowth from the nuclear envelope

• 来源期刊: 分子细胞生物学报（英文版）
• 年，卷（期）: 2019,（11）
• 页码范围: 944-955
• 页数: 12页
• 语种: 英文
• DOI: 10.1093/jmcb/mjz038

摘要

Microtubules grow not only from the centrosome but also from various noncentrosomal microtubule-organizing centers (MTOCs),including the nuclear envelope (NE) and pre-existing microtubules.The evolutionadly conserved proteins Mto1/CDK5RAP2 and Alp14/TOG/XMAP215 have been shown to be involved in promoting microtubule nucleation.However,it has remained elusive as to how the microtubule nucleation promoting factors are specified to vadous noncentrosomal MTOCs,particularly the NE,and how these proteins coordinate to organize microtubule assembly.Here,we demonstrate that in the fission yeast Schizosocchoromyces pombe,efficient interphase microtubule growth from the NE requires Alp7/TACC,Alp14/TOG/XMAP215,and Mto1/CDK5RAP2.The absence of Alp7,Alp14,or Mto1 compromises microtubule regrowth on the NE in cells undergoing microtubule repolymedzation.We further demonstrate that Alp7 and Mto1 interdependently localize to the NE in cells without microtubules and that Alp14 localizes to the NE in an Alp7 and Mto1-dependent manner.Tethedng Mto1 to the NE in cells lacking Alp7 partially restores microtubule number and the efficiency of microtubule generation from the NE.Hence,our study delineates that Alp7,Alp14,and Mto1 work in concert to regulate interphase microtubule regrowth on the NE.