NRG1, a repressor of filamentous growth in C.albicans, is down-regulated during filament induction
NRG1, a repressor of filamentous growth in C.albicans, is down-regulated during filament induction
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DOI：
10.1093/emboj/20.17.4753
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发表时间：
2001-09-03
期刊：
影响因子：
11.4
通讯作者：
Johnson, AD
中科院分区：
文献类型：
--
作者：
Braun, BR;Kadosh, D;Johnson, AD
为了响应各种外部信号，真菌病原体白色念珠菌经历了椭圆形单细胞（芽生孢子）和由端对端连接的细长细胞组成的丝状体之间的转变。在这里，我们确定了一个DNA结合蛋白，Nrg1，抑制丝状生长念珠菌可能通过共同抑制Tup1。NRG 1突变体细胞在非丝状诱导条件下主要是丝状的，并且它们的集落形态类似于TUP 1突变体。我们还确定了两个特异性的基因，ECE1和HWP 1，其转录抑制Nrg1在非诱导条件下。这些基因构成了Tup1控制下的基因的一个子集，进一步证明了Nrg1通过招募Tup1靶向基因发挥作用。我们发现，在血清中生长在37 degreesC，一个有力的诱导丝状生长，导致NRG1 mRNA的减少，这表明丝状生长是由NRG1的下调诱导。与这一想法一致，NRG 1从非调控启动子的表达部分阻断了丝状生长的诱导。
In response to a variety of external signals, the fungal pathogen Candida albicans undergoes a transition between ellipsoidal single cells (blastospores) and filaments composed of elongated cells attached end-to-end. Here we identify a DNA-binding protein, Nrg1, that represses filamentous growth in Candida probably by acting through the co-repressor Tup1. nrg1 mutant cells are predominantly filamentous under non-filament-inducing conditions and their colony morphology resembles that of tup1 mutants. We also identify two filament-specific genes, ECE1 and HWP1, whose transcription is repressed by Nrg1 under noninducing conditions. These genes constitute a subset of those under Tup1 control, providing further evidence that Nrg1 acts by recruiting Tup1 to target genes. We show that growth in serum at 37 degreesC, a potent inducer of filamentous growth, causes a reduction of NRG1 mRNA, suggesting that filamentous growth is induced by the down-regulation of NRG1. Consistent with this idea, expression of NRG1 from a non-regulated promoter partially blocks the induction of filamentous growth.