The Drosophila trithorax group protein Kismet facilitates an early step in transcriptional elongation by RNA Polymerase II
The Drosophila trithorax group protein Kismet facilitates an early step in transcriptional elongation by RNA Polymerase II
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DOI：
10.1242/dev.01713
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发表时间：
2005-04-01
期刊：
影响因子：
4.6
通讯作者：
Tamkun, JW
中科院分区：
文献类型：
--
作者：
Srinivasan, S;Armstrong, JA;Tamkun, JW
果蝇三胸群基因kismet （kis）在Polycomb （Pc）基因外抑制因子筛选中被鉴定出来，并在分割和确定体段身份中发挥重要作用。kis编码的两个主要蛋白之一（kiss - l）与atp依赖性染色质重塑因子的SWI2/SNF2和CHD家族成员有关。为了阐明kiss - l在基因表达中的作用，我们研究了其在幼虫唾液腺多丝染色体上的分布。kiss - l与几乎所有转录活性染色质位点相关，其模式在很大程度上与RNA聚合酶II （Pol II）重叠。突变体幼虫多烯染色体上的延长型Pol II和延长因子SPT6、CHD1水平显著降低。相比之下，kiss - l功能的丧失并不影响PC与染色质的结合或Pol II向启动子的募集。这些数据表明，kiss - l促进了Pol II转录延伸的早期步骤。
The Drosophila trithorax group gene kismet (kis) was identified in a screen for extragenic suppressors of Polycomb (Pc) and subsequently shown to play important roles in both segmentation and the determination of body segment identities. One of the two major proteins encoded by kis (KIS-L) is related to members of the SWI2/SNF2 and CHD families of ATP-dependent chromatin-remodeling factors. To clarify the role of KIS-L in gene expression, we examined its distribution on larval salivary gland polytene chromosomes. KIS-L is associated with virtually all sites of transcriptionally active chromatin in a pattern that largely overlaps that of RNA Polymerase II (Pol II). The levels of elongating Pol II and the elongation factors SPT6 and CHD1 are dramatically reduced on polytene chromosomes from kis mutant larvae. By contrast, the loss of KIS-L function does not affect the binding of PC to chromatin or the recruitment of Pol II to promoters. These data suggest that KIS-L facilitates an early step in transcriptional elongation by Pol II.