Microtubule-organizing centers of Aspergillus nidulans are anchored at septa by a disordered protein
Microtubule-organizing centers of Aspergillus nidulans are anchored at septa by a disordered protein
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DOI：
10.1111/mmi.13763
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发表时间：
2017-10-01
影响因子：
3.6
通讯作者：
Fischer, Reinhard
中科院分区：
文献类型：
--
作者：
Zhang, Ying;Gao, Xiaolei;Fischer, Reinhard
微管组织中心（MTOCs）是一种大型的多亚基蛋白质复合物。裂糖菌在纺锤极体中含有MTOCs，在分裂面中含有瞬时MTOCs，在间期细胞中含有核膜相关MTOCs。在丝状真菌芽曲霉中描述了spb和间隔相关的mtoc。虽然与S. pombe的eMTOCs相当，但A. nidulans的sMTOCS是永久性的隔膜相关结构。人们对sMTOCs的组成知之甚少，也不知道它们是如何靶向间隔的。在这里，我们发现在a . nidulans中，几种SPB外斑块蛋白也定位于sMTOCs，而其他SPB蛋白则不定位于sMTOCs，包括SfiA（酿酒酵母中SPB复制所需的蛋白质）和S. pombe和PcpA （SPB内斑块中-TuSCs的锚定蛋白）。nidulans紊乱蛋白Spa18（Mto2）和含有中心体结构域的蛋白ApsB（Mto1）是将-TuRC组分GcpC招募到smtoc和从间隔中播种MT形成所必需的。通过测试不同的间隔相关蛋白在sMTOC功能中的作用，确定了Spa10。它形成一个间隔孔盘结构，将Spa18和ApsB招募到间隔，这是sMTOC活性所必需的。这是隔区特异性蛋白Spa10作为一类特定mtoc锚定蛋白的第一个证据。
Microtubule-organizing centers (MTOCs) are large, multi-subunit protein complexes. Schizosaccharomyces pombe harbors MTOCs at spindle pole bodies, transient MTOCs in the division plane (eMTOCs) and nuclear-envelope associated MTOCs in interphase cells (iMTOCs). In the filamentous fungus Aspergillus nidulans SPBs and septum-associated MTOCs were described. Although comparable to S. pombe eMTOCs, A. nidulans sMTOCS are permanent septum-associated structures. The composition of sMTOCs is poorly understood and how they are targeted to septa was unknown. Here, we show that in A. nidulans several SPB outer plaque proteins also locate to sMTOCs while other SPB proteins do not, including SfiA, a protein required for SPB duplication in Saccharomyces cerevisiae and S. pombe and PcpA, the anchor for -TuSCs at the SPB inner plaque. The A. nidulans disordered protein Spa18(Mto2) and the centrosomin-domain containing protein ApsB(Mto1) were required for recruiting the -TuRC component GcpC to sMTOCs and for seeding MT formation from septa. Testing different septum-associated proteins for a role in sMTOC function, Spa10 was identified. It forms a septal pore disc structure, recruits Spa18 and ApsB to septa and is required for sMTOC activity. This is the first evidence for a septum-specific protein, Spa10, as anchor for a specific class of MTOCs.