Plk phosphorylation regulates the microtubule-stabilizing protein TCTP
Plk phosphorylation regulates the microtubule-stabilizing protein TCTP
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DOI：
10.1128/mcb.22.17.6209-6221.2002
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发表时间：
2002-09-01
影响因子：
5.3
通讯作者：
Yarm, FR
中科院分区：
文献类型：
--
作者：
Yarm, FR
根据其各自的定位和突变表型，有丝分裂 polo 样激酶与双极纺锤体的形成和功能有关。迄今为止，这种假定的调节仅限于驱动蛋白样运动蛋白、中心体结构蛋白和两种微管相关蛋白（MALP）。在这项研究中，另一种纺锤体调节蛋白，哺乳动物非 MAP 微管结合和稳定蛋白，翻译控制肿瘤蛋白 (TCTP)，通过双杂交筛选被鉴定为假定的 Plk 相互作用克隆。 Plk 在体外使 TCTP 在两个丝氨酸残基上磷酸化，并与有丝分裂细胞裂解物中针对 TCTP 的大部分激酶活性共同分级。此外，这些位点被证明在体内被磷酸化。 TCTP Plk 磷酸化位点缺陷突变体的过度表达诱导多核细胞、具有浓缩球状核的圆形细胞和经历细胞死亡的细胞数量急剧增加，与报道的抗 Plk 抗体显微注射和低浓度紫杉醇治疗表型相似。这些结果表明，磷酸化降低了 TCTP 的微管稳定活性，并促进中期后微管动力学的增加。
The mitotic polo-like kinases have been implicated in the formation and function of bipolar spindles on the basis of their respective localizations and mutant phenotypes. To date, this putative regulation has been limited to a kinesin-like motor protein, a centrosomal structural protein, and two microtubule-associated proteins (MALPs). In this study, another spindle-regulating protein, the mammalian non-MAP microtubule-binding and -stabilizing protein, the translationally controlled tumor protein (TCTP), was identified as a putative Plk-interacting clone by a two-hybrid screen. Plk phosphorylates TCTP on two serine residues in vitro and cofractionates with the majority of kinase activity toward TCTP in mitotic cell lysates. In addition, these sites were demonstrated to be phosphorylated in vivo. Overexpression of a Plk phosphorylation site-deficient mutant of TCTP induced a dramatic increase in the number of multinucleate cells, rounded cells with condensed ball-like nuclei, and cells undergoing cell death, similar to both the reported anti-Plk antibody microinjection and the low-concentration taxol treatment phenotypes. These results suggest that phosphorylation decreases the microtubule-stabilizing activity of TCTP and promotes the increase in microtubule dynamics that occurs after metaphase.