Department of Genetics, The University of Melbourne, Parkville 3010, Australia.
Department of Plant Pathology, Kansas State University, 4024 Throckmorton Hall, Manhattan, KS 66506-5502 USA.
Microbiology (Reading). 2009 Dec;155(Pt 12):3868-3880. doi: 10.1099/mic.0.031252-0. Epub 2009 Jul 23.
The Aspergillus nidulans transcription factor AreA is a key regulator of nitrogen metabolic gene expression. AreA contains a C-terminal GATA zinc finger DNA-binding domain and activates expression of genes necessary for nitrogen acquisition. Previous studies identified AreB as a potential negative regulator of nitrogen catabolism showing similarity with Penicillium chrysogenum NreB and Neurospora crassa ASD4. The areB gene encodes multiple products containing an N-terminal GATA zinc finger and a leucine zipper motif. We deleted the areB gene and now show that AreB negatively regulates AreA-dependent nitrogen catabolic gene expression under nitrogen-limiting or nitrogen-starvation conditions. AreB also acts pleiotropically, with functions in growth, conidial germination and asexual development, though not in sexual development. AreB overexpression results in severe growth inhibition, aberrant cell morphology and reduced AreA-dependent gene expression. Deletion of either the DNA-binding domain or the leucine zipper domain results in loss of both nitrogen and developmental phenotypes.
构巢曲霉转录因子 AreA 是氮代谢基因表达的关键调节剂。AreA 含有一个 C 端 GATA 锌指 DNA 结合域，并激活氮获取所需基因的表达。先前的研究表明，AreB 是氮分解代谢的潜在负调节剂，与产黄青霉 NreB 和粗糙脉孢菌 ASD4 具有相似性。areB 基因编码多个包含 N 端 GATA 锌指和亮氨酸拉链模体的产物。我们删除了 areB 基因，现在表明，在氮限制或氮饥饿条件下，AreB 负调控依赖于 AreA 的氮分解代谢基因表达。AreB 还具有多效性，在生长、分生孢子萌发和无性发育中发挥作用，但在有性发育中不起作用。AreB 的过表达导致严重的生长抑制、异常的细胞形态和依赖于 AreA 的基因表达减少。缺失 DNA 结合域或亮氨酸拉链域都会导致氮和发育表型的丧失。
