Holland Andrew J, Reis Rita M, Niessen Sherry, Pereira Cláudia, Andres Douglas A, Spielmann H Peter, Cleveland Don W, Desai Arshad, Gassmann Reto
Ludwig Institute for Cancer Research/Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto 4150-180, Portugal Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, Porto 4150-180, Portugal.
Mol Biol Cell. 2015 May 15;26(10):1845-56. doi: 10.1091/mbc.E14-11-1560. Epub 2015 Mar 25.
The clinical interest in farnesyltransferase inhibitors (FTIs) makes it important to understand how these compounds affect cellular processes involving farnesylated proteins. Mitotic abnormalities observed after treatment with FTIs have so far been attributed to defects in the farnesylation of the outer kinetochore proteins CENP-E and CENP-F, which are involved in chromosome congression and spindle assembly checkpoint signaling. Here we identify the cytoplasmic dynein adaptor Spindly as an additional component of the outer kinetochore that is modified by farnesyltransferase (FTase). We show that farnesylation of Spindly is essential for its localization, and thus for the proper localization of dynein and its cofactor dynactin, to prometaphase kinetochores and that Spindly kinetochore recruitment is more severely affected by FTase inhibition than kinetochore recruitment of CENP-E and CENP-F. Molecular replacement experiments show that both Spindly and CENP-E farnesylation are required for efficient chromosome congression. The identification of Spindly as a new mitotic substrate of FTase provides insight into the causes of the mitotic phenotypes observed with FTase inhibitors.
法尼基转移酶抑制剂（FTIs）在临床上备受关注，因此了解这些化合物如何影响涉及法尼基化蛋白的细胞过程至关重要。迄今为止，FTIs处理后观察到的有丝分裂异常归因于外着丝粒蛋白CENP-E和CENP-F的法尼基化缺陷，这些蛋白参与染色体排列和纺锤体组装检查点信号传导。在此，我们鉴定出细胞质动力蛋白衔接蛋白Spindly是外着丝粒的另一个组成部分，它会被法尼基转移酶（FTase）修饰。我们表明，Spindly的法尼基化对其定位至关重要，因此对于动力蛋白及其辅因子动力蛋白激活蛋白向有丝分裂前中期着丝粒的正确定位也至关重要，并且Spindly着丝粒募集受FTase抑制的影响比CENP-E和CENP-F的着丝粒募集更严重。分子置换实验表明，Spindly和CENP-E的法尼基化都是有效染色体排列所必需的。将Spindly鉴定为FTase的一种新的有丝分裂底物，有助于深入了解FTase抑制剂所观察到的有丝分裂表型的原因。
