Cloning of USO1, yeast secretory gene, homologue from Aspergillus fungi

一般来说，曲霉真菌在培养基中分泌大量的蛋白质，而酵母则不分泌。我们之前报道了USO1基因的分离，这是细胞内蛋白质运输所必需的。Uso1p由球状头（780 aa）、盘状尾（1000 aa）和c端酸性氨基酸簇组成。我们检索了细粒曲霉的EST数据库，找到了与哺乳动物同源基因Uso1p和p115的酸性结构域同源的序列。根据该序列设计引物，从拟南芥基因组DNA中克隆出USO1同源基因，并命名为USO1。我们还分离了相应的cDNA，并对其序列进行了分析。usoA基因含有5个内含子，编码1103个氨基酸的蛋白质。预测的UsoA蛋白由球形头（680 aa）、盘状尾（400 aa）和c端酸性结构域组成，与Uso1p/p115保守。UsoA与粗神经孢子虫（Neurospora crassa， S.cerevisiae, 0.5）的Uso1或p115的同源性分别为46%、29%、29%和26%。庞贝和牛。我们重点研究了usoA基因的抑制对真菌细胞内蛋白转运的影响。

In general, Aspergillus fungi secrete secrete large amount of protein in the medium but not yeast. We previously reported the isolation of the USO1 gene, which is required for intracellular protein transport. Uso1p is composed of globular head (780 aa), coiled-coil tail (1000 aa), and C-terminal acidic amino acids cluster.We searched EST database of Aspergillus nidulans and found a homologous sequence to the acidic domain of Uso1p and p115, mammalian homologue. We designed the primers based on the sequence and cloned a USO1 homologue gene from the genomic DNA of A.nidulans and named the gene as usoA.. We also isolated the corresponding cDNA and the sequence was analyzed. The usoA gene contains five introns and encodes a protein of 1103 amino acids. Predicted UsoA protein is composed of globular head (680 aa), coiled-coil tail (400 aa) and C-terminal acidic domain, which is conserved with Uso1p/p115. UsoA shows 46%, 29%, 29% and 26% identity to Uso1 or p115 from Neurospora crassa, S.cerevisiae, .5. pombe and bovine. We focus on investigation of intracellular protein transport in the fungus cells by repression of the usoA gene.