NuSAP, a novel microtubule-associated protein involved in mitotic spindle organization.
NuSAP, a novel microtubule-associated protein involved in mitotic spindle organization.
复制标题
NUSAP是一种与有丝分裂纺锤体组织有关的新型微管相关蛋白。
DOI：
10.1083/jcb.200302129
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发表时间：
2003-09-15
影响因子：
7.8
通讯作者：
Carmeliet, Geert
中科院分区：
文献类型：
--
作者：
Raemaekers, Tim;Ribbeck, Katharina;Beaudouin, Joel;Annaert, Wim;Van Camp, Mark;Stockmans, Ingrid;Smets, Nico;Bouillon, Roger;Ellenberg, Jan;Carmeliet, Geert
在这里，我们报道了核核纺锤体相关蛋白（NuSAP）的鉴定，这是一种新的55-kD的脊椎动物蛋白，在增殖细胞中选择性表达。其mRNA和蛋白水平在G2向有丝分裂过渡时达到峰值，在细胞分裂后急剧下降。对固定和活的哺乳动物细胞的显微镜分析表明，NuSAP在间期主要是核核的，在有丝分裂时主要定位于中央纺锤体微管。在体外实验中证实了NuSAP与微管的直接相互作用。NuSAP的过表达导致间期细胞中细胞质微管的深度捆绑，这依赖于cooh末端微管结合域。相反，RNA干扰导致NuSAP耗损导致有丝分裂纺锤体异常、染色体分离缺陷和细胞质分裂。此外，许多nusap缺失的间期细胞细胞核变形。NuSAP的过表达和低表达均能抑制细胞增殖。这些结果表明NuSAP在纺锤体微管组织中起关键作用。
Here, we report on the identification of nucleolar spindle–associated protein (NuSAP), a novel 55-kD vertebrate protein with selective expression in proliferating cells. Its mRNA and protein levels peak at the transition of G2 to mitosis and abruptly decline after cell division. Microscopic analysis of both fixed and live mammalian cells showed that NuSAP is primarily nucleolar in interphase, and localizes prominently to central spindle microtubules during mitosis. Direct interaction of NuSAP with microtubules was demonstrated in vitro. Overexpression of NuSAP caused profound bundling of cytoplasmic microtubules in interphase cells, and this relied on a COOH-terminal microtubule-binding domain. In contrast, depletion of NuSAP by RNA interference resulted in aberrant mitotic spindles, defective chromosome segregation, and cytokinesis. In addition, many NuSAP-depleted interphase cells had deformed nuclei. Both overexpression and knockdown of NuSAP impaired cell proliferation. These results suggest a crucial role for NuSAP in spindle microtubule organization.