Youssar Loubna, Avalos Javier
Departamento de Genética, Universidad de Sevilla, E-41012 Sevilla, Spain.
Fungal Genet Biol. 2006 Nov;43(11):752-63. doi: 10.1016/j.fgb.2006.05.003. Epub 2006 Jun 27.
The gene cut-1 from Neurospora encodes a protein of the haloacid dehalogenase (HAD) family, a group of enzymes usually associated to phosphatase or phosphotransferase activities. Loss of cut-1 function results in an osmosensitive phenotype and its transcription is induced by high osmotic pressure or heat-shock, but not by other stressing conditions tested. Unexpectedly, cut-1 transcript levels markedly decrease following illumination in the wild type and in some mutants tested, such as bd and vvd. The reduction was less pronounced in wc-1 and wc-2 mutants, indicating that this photoresponse is principally mediated by the WC system, a conclusion further supported by the lack of effect of blue light in a wc-1 mutant. Additionally, cut-1 mRNA levels are much higher in the dark in wc, vvd, bd, and cut mutants, showing the involvement of these genes in a cut-1 down-regulation mechanism. In the cases investigated, the mRNA levels of these strains increased further under high osmotic conditions, indicating an independent derepression effect. The environmental or genetic factors influencing cut-1 expression have no significant effect on the mRNA levels of two additional Neurospora genes encoding HAD proteins.
来自粗糙脉孢菌的cut-1基因编码一种卤代酸脱卤酶（HAD）家族的蛋白质，这是一组通常与磷酸酶或磷酸转移酶活性相关的酶。cut-1功能的丧失会导致渗透敏感表型，其转录由高渗透压或热激诱导，但不受其他测试的胁迫条件诱导。出乎意料的是，在野生型以及一些测试的突变体（如bd和vvd）中，光照后cut-1转录水平显著降低。在wc-1和wc-2突变体中这种降低不太明显，表明这种光反应主要由WC系统介导，蓝光对wc-1突变体无影响进一步支持了这一结论。此外，在wc、vvd、bd和cut突变体中，cut-1 mRNA水平在黑暗中要高得多，表明这些基因参与了cut-1的下调机制。在所研究的案例中，这些菌株的mRNA水平在高渗条件下进一步增加，表明存在独立的去阻遏效应。影响cut-1表达的环境或遗传因素对另外两个编码HAD蛋白的粗糙脉孢菌基因的mRNA水平没有显著影响。
