Septin ring assembly is regulated by Spt20, a structural subunit of the SAGA complex
Septin ring assembly is regulated by Spt20, a structural subunit of the SAGA complex
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Septin 环组装由 SAGA 复合体的结构亚基 Spt20 调节
DOI：
10.1242/jcs.151910
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发表时间：
2014-09-15
影响因子：
4
通讯作者：
Lu, Hong
中科院分区：
文献类型：
--
作者：
Lei, Bingkun;Zhou, Nan;Lu, Hong
精确的细胞分裂需要高阶隔蛋白结构的正确组装。在裂殖酵母（裂殖酵母）中，Spn 1-Spn 4在分裂位点组装成初级隔蛋白环，随后Mid 2的募集导致稳定的隔蛋白环。然而，对这一关键过程的监管知之甚少。在这里，我们发现，Spt 20，Spt-Ada-Gcn 5-乙酰转移酶（佐贺）转录激活复合物的结构亚基的缺失，造成了严重的细胞分离缺陷。该缺陷主要是由于受损的隔蛋白环组装，因为80%的spt 20 Delta细胞在分裂位点失去了隔蛋白环。spt 20部分通过mid 2（+）的转录激活调节隔蛋白环组装。Spt 20在体外也与Spn 2和Mid 2相互作用，并且在体内与环的其他组分相关。Spt 20与septin环共定位，但当septin环分裂时没有分离。重要的是，Spt 20调节Septin环的稳定性，并且是Mid 2募集所需的。Spt 20在隔蛋白环组装中的转录依赖性和非依赖性作用突出了佐贺亚基对一个过程的多方面调节。
Accurate cell division requires the proper assembly of high-order septin structures. In fission yeast (Schizosaccharomyces pombe), Spn1-Spn4 are assembled into a primary septin ring at the division site, and the subsequent recruitment of Mid2 to the structure results in a stable septin ring. However, not much is known about the regulation of this key process. Here, we found that deletion of Spt20, a structural subunit of the Spt-Ada-Gcn5-acetyltransferase (SAGA) transcriptional activation complex, caused a severe cell separation defect. The defect was mainly due to impaired septin ring assembly, as 80% of spt20 Delta cells lost septin rings at the division sites. Spt20 regulates septin ring assembly partially through the transcriptional activation of mid2(+). Spt20 also interacted with Spn2 and Mid2 in vitro and was associated with other components of the ring in vivo. Spt20 colocalized with the septin ring, but did not separate when the septin ring split. Importantly, Spt20 regulated the stability of the septin ring and was required for the recruitment of Mid2. The transcription-dependent and -independent roles of Spt20 in septin ring assembly highlight a multifaceted regulation of one process by a SAGA subunit.