Caenorhabditis elegans TBX-2 Directly Regulates Its Own Expression in a Negative Autoregulatory Loop.
Caenorhabditis elegans TBX-2 Directly Regulates Its Own Expression in a Negative Autoregulatory Loop.
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DOI：
10.1534/g3.115.018101
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发表时间：
2015-04-14
期刊：
影响因子：
--
通讯作者：
Okkema PG
中科院分区：
文献类型：
--
作者：
Milton AC;Okkema PG
T-box基因通常表现出动态的表达模式，其表达水平对正常功能至关重要。尽管这些基因很重要，但人们对T-box基因的调控知之甚少。我们重点研究了秀丽线虫基因tbx-2，以了解T-box基因的表达是如何调控的，在这里，我们证明了tbx-2本身在一个负的自我调节环路中直接抑制自己的表达。Tbx-2对于正常的咽肌发育是必不可少的，Tbx-2启动子GFP融合(Ptbx-2：：GFP)在胚胎发育过程中在咽部瞬时表达，在幼虫和成虫的少量头部神经元中表达。Tbx-2功能降低导致Ptbx-2：：GFP在幼虫和成虫的缝隙细胞和肠道中异位表达。Tbx-2启动子内潜在的T-box结合位点的突变导致了异位表达Ptbx-2：：GFP的相似模式，染色质免疫沉淀分析表明Tbx-2在体内结合了这些结合位点。Tbx-2突变体中Ptbx-2：：GFP的异位表达模式与影响NF-Y复合体的突变体中的Ptbx-2：：GFP表达模式非常相似，我们的结果比较了Tbx-2和nfyb-1的单突变体和双突变体，表明Tbx-2和NF-Y在单一途径中抑制Tbx-2启动子。Tbx-2启动子是Tbx-2的第一个直接靶点，我们用它来研究SUMO化是否对Tbx-2的抑制是必不可少的。糖基化途径组分的RNAi敲除导致Ptbx-2：：GFP在Seam细胞和肠道中异位表达。异位的Ptbx-2：：GFP也在合体皮下组织中观察到，这表明tbx-2启动子受到其他SUMO化依赖机制的抑制，或者SUMO化减少导致缝细胞核在与合体细胞皮下组织融合时发生稳定的变化。我们认为，负自动调节是一种重要的机制，可以精确控制TBX-2的表达水平，并可能允许发育过程中基因表达的快速变化。
T-box genes often exhibit dynamic expression patterns, and their expression levels can be crucial for normal function. Despite the importance of these genes, there is little known about T-box gene regulation. We have focused on the Caenorhabditis elegans gene tbx-2 to understand how T-box gene expression is regulated, and here we demonstrate TBX-2 itself directly represses its own expression in a negative autoregulatory loop. tbx-2 is essential for normal pharyngeal muscle development, and a tbx-2 promoter gfp fusion (Ptbx-2::gfp) is transiently expressed in the pharynx during embryogenesis and in a small number of head neurons in larvae and adults. Reduced tbx-2 function resulted in ectopic Ptbx-2::gfp expression in the seam cells and gut in larvae and adults. Mutation of potential T-box binding sites within the tbx-2 promoter resulted in a similar pattern of ectopic Ptbx-2::gfp expression, and chromatin immunoprecipitation analyses show TBX-2 binds these sites in vivo. This pattern of ectopic Ptbx-2::gfp expression in tbx-2 mutants was very similar to that observed in mutants affecting the NF-Y complex, and our results comparing tbx-2 and nfyb-1 single- and double mutants suggest TBX-2 and NF-Y function in a single pathway to repress the tbx-2 promoter. The tbx-2 promoter is the first direct target identified for TBX-2, and we used it to ask whether SUMOylation is essential for TBX-2 repression. RNAi knockdown of SUMOylation pathway components led to ectopic Ptbx-2::gfp expression in the seam cells and gut. Ectopic Ptbx-2::gfp also was observed in the syncytial hypodermis, suggesting either the tbx-2 promoter is repressed by other SUMOylation dependent mechanisms, or that decreased SUMOylation leads to stable changes in seam cell nuclei as they fuse with the syncytial hypodermis. We suggest negative autoregulation is an important mechanism that allows precise control of tbx-2 expression levels and may allow rapid changes in gene expression during development.
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影响因子：
2.7
作者：
Chowdhuri, Sinchita Roy;Crum, Tanya;Okkema, Peter G.
通讯作者：
Okkema, Peter G.
影响因子：
10.7
作者：
Cheatle Jarvela AM;Brubaker L;Vedenko A;Gupta A;Armitage BA;Bulyk ML;Hinman VF
通讯作者：
Hinman VF
DOI：
10.1126/science.1162327
发表时间：
2009-06-26
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Badis G;Berger MF;Philippakis AA;Talukder S;Gehrke AR;Jaeger SA;Chan ET;Metzler G;Vedenko A;Chen X;Kuznetsov H;Wang CF;Coburn D;Newburger DE;Morris Q;Hughes TR;Bulyk ML
通讯作者：
Bulyk ML
影响因子：
8
作者：
Huber, Paul;Crum, Tanya;Clary, Lynn M.;Ronan, Tom;Packard, Adelaide V.;Okkema, Peter G.
通讯作者：
Okkema, Peter G.
影响因子：
3.3
作者：
Cai, Qingchun;Sun, Yinyan;Zhang, Hong
通讯作者：
Zhang, Hong