Spindle positioning in human cells relies on proper centriole formation and on the microcephaly proteins CPAP and STIL
Spindle positioning in human cells relies on proper centriole formation and on the microcephaly proteins CPAP and STIL
复制标题
DOI：
10.1242/jcs.089888
复制
发表时间：
2011-11-15
影响因子：
4
通讯作者：
Goenczy, Pierre
中科院分区：
文献类型：
--
作者：
Kitagawa, Daiju;Kohlmaier, Gregor;Goenczy, Pierre
MCPH(常染色体隐性遗传性原发性小头症)患者表现出大脑发育受损，可能是由于神经前体细胞的功能受损。目前已鉴定出7个MCPH基因座，其中1个编码中心体蛋白4.1相关蛋白(CPAP；也称为着丝粒蛋白J，CENPJ)。CPAP是一种集中在中心体的大卷曲蛋白，该结构由两个中心粒和周围的中心周围物质(PCM)组成。CPAP的缺失会损害中心粒的形成，而CPAP的过度表达会导致中心粒过长。CPAP MCPH患者突变影响大脑发育的机制尚不清楚。在这里，我们确定了CPAP蛋白结构域对其中心粒定位以及对中心粒的延长和形成至关重要。此外，我们证明了类似于CPAP MCPH患者突变的条件损害了组织培养细胞中中心粒的形成。利用粘合剂微图，我们揭示了这种缺陷与主轴位置的随机性有关。此外，我们证明了MCPH蛋白SCL/TAL1中断位点(STIL)对于中心粒的形成和适当的纺锤体位置也是必不可少的。我们的发现与CPAP和STIL突变导致MCPH的观点是一致的，这是因为在大脑发育过程中前体细胞中的纺锤体位置异常。
Patients with MCPH (autosomal recessive primary microcephaly) exhibit impaired brain development, presumably due to the compromised function of neuronal progenitors. Seven MCPH loci have been identified, including one that encodes centrosome protein 4.1 associated protein (CPAP; also known as centromere protein J, CENPJ). CPAP is a large coiled-coil protein enriched at the centrosome, a structure that comprises two centrioles and surrounding pericentriolar material (PCM). CPAP depletion impairs centriole formation, whereas CPAP overexpression results in overly long centrioles. The mechanisms by which CPAP MCPH patient mutations affect brain development are not clear. Here, we identify CPAP protein domains crucial for its centriolar localization, as well as for the elongation and the formation of centrioles. Furthermore, we demonstrate that conditions that resemble CPAP MCPH patient mutations compromise centriole formation in tissue culture cells. Using adhesive micropatterns, we reveal that such defects correlate with a randomization of spindle position. Moreover, we demonstrate that the MCPH protein SCL/TAL1 interrupting locus (STIL) is also essential for centriole formation and for proper spindle position. Our findings are compatible with the notion that mutations in CPAP and STIL cause MCPH because of aberrant spindle positioning in progenitor cells during brain development.