Piotrowska M, Natorff R, Paszewski A
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw.
Mol Gen Genet. 2000 Oct;264(3):276-82. doi: 10.1007/s004380000319.
sconC, which encodes a negative regulator of sulphur metabolism in Aspergillus nidulans was cloned, sequenced, and found to belong to the highly conserved family of SKP1 genes essential for many cell functions, including cell cycle regulation. The ORF of 722 bp, encoding a protein of 161 amino acids, is interrupted by four introns. There is a fifth intron (135 bp long) in the upstream untranslated sequence. Two point mutations in conserved regions were identified in the mutant alleles sconC3 and sconC1, which result in relief of sulphur metabolite repression. The SCONC protein contains the PEST sequence common for proteins that are subject to rapid turnover. Transformation of the sconC3 mutant with sconB+ restores the wild-type phenotype. The sconB gene encodes a protein containing the F-box, a domain known to interact with Skp1 proteins. By analogy with other systems, it seems likely that the SCONC protein interacts with SCONB. sconC mRNA is present in the sconC3 and sconB2 mutants and the level of the sconC transcript seems not to be significantly regulated by supplementation of the medium with sulphur.
克隆并测序了构巢曲霉中编码硫代谢负调控因子的sconC，发现它属于对包括细胞周期调控在内的许多细胞功能至关重要的高度保守的SKP1基因家族。722 bp的开放阅读框编码一个161个氨基酸的蛋白质，被四个内含子打断。在上游非翻译序列中有一个第五内含子（长135 bp）。在突变等位基因sconC3和sconC1中鉴定出保守区域的两个点突变，这导致硫代谢物阻遏的缓解。SCONC蛋白含有易快速周转的蛋白质常见的PEST序列。用sconB+转化sconC3突变体可恢复野生型表型。sconB基因编码一种含有F-box的蛋白质，F-box是一个已知与Skp1蛋白相互作用的结构域。与其他系统类似，SCONC蛋白似乎与SCONB相互作用。sconC mRNA存在于sconC3和sconB2突变体中，并且sconC转录本的水平似乎不受培养基中添加硫的显著调节。
