De Kuntal, Bolaños-Villegas Pablo, Mitra Sayantan, Yang Xiaohui, Homan Garret, Jauh Guang-Yuh, Makaroff Christopher A
Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056.
University of Costa Rica, Fabio Baudrit Agricultural Research Station, La Garita de Alajuela, 20102, Costa Rica Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan Biotechnology Center, National Chung-Hsing University, Taichung 402, Taiwan.
Plant Cell. 2016 Feb;28(2):521-36. doi: 10.1105/tpc.15.00781. Epub 2016 Jan 26.
Sister chromatid cohesion, which is mediated by the cohesin complex, is essential for the proper segregation of chromosomes during mitosis and meiosis. Stable binding of cohesin with chromosomes is regulated in part by the opposing actions of CTF7 (CHROMOSOME TRANSMISSION FIDELITY7) and WAPL (WINGS APART-LIKE). In this study, we characterized the interaction between Arabidopsis thaliana CTF7 and WAPL by conducting a detailed analysis of wapl1-1 wapl2 ctf7 plants. ctf7 plants exhibit major defects in vegetative growth and development and are completely sterile. Inactivation of WAPL restores normal growth, mitosis, and some fertility to ctf7 plants. This shows that the CTF7/WAPL cohesin system is not essential for mitosis in vegetative cells and suggests that plants may contain a second mechanism to regulate mitotic cohesin. WAPL inactivation restores cohesin binding and suppresses ctf7-associated meiotic cohesion defects, demonstrating that WAPL and CTF7 function as antagonists to regulate meiotic sister chromatid cohesion. The ctf7 mutation only had a minor effect on wapl-associated defects in chromosome condensation and centromere association. These results demonstrate that WAPL has additional roles that are independent of its role in regulating chromatin-bound cohesin.
由黏连蛋白复合体介导的姐妹染色单体黏连，对于有丝分裂和减数分裂过程中染色体的正确分离至关重要。黏连蛋白与染色体的稳定结合部分受CTF7（染色体传递保真因子7）和WAPL（类翼状分离蛋白）的相反作用调控。在本研究中，我们通过对wapl1-1 wapl2 ctf7植株进行详细分析，来表征拟南芥CTF7与WAPL之间的相互作用。ctf7植株在营养生长和发育方面表现出主要缺陷，并且完全不育。WAPL的失活恢复了ctf7植株的正常生长、有丝分裂以及部分育性。这表明CTF7/WAPL黏连蛋白系统对于营养细胞中的有丝分裂并非必不可少，并提示植物可能含有第二种调节有丝分裂黏连蛋白的机制。WAPL失活恢复了黏连蛋白结合，并抑制了与ctf7相关的减数分裂黏连缺陷，表明WAPL和CTF7作为拮抗剂发挥作用，以调节减数分裂中的姐妹染色单体黏连。ctf7突变对wapl相关的染色体浓缩和着丝粒关联缺陷仅产生轻微影响。这些结果表明，WAPL具有与其在调节染色质结合黏连蛋白中的作用无关的其他作用。
