Shimoi H, Iimura Y, Obata T
National Research Institute of Brewing, Tokyo.
J Biochem. 1995 Aug;118(2):302-11. doi: 10.1093/oxfordjournals.jbchem.a124907.
A yeast cell wall glycoprotein with a molecular weight of 40,000, named gp40, was solubilized from SDS-extracted cell wall of Saccharomyces cerevisiae by incubation with Rarobacter faecitabidus protease I, which is a yeast-lytic enzyme. Based on its amino acid sequence, we cloned and sequenced the gene encoding the precursor of gp40, named CWP1; cell wall protein gene. The DNA sequence of the CWP1 gene was identical to YKL443, an open reading frame identified in a genome sequencing program for yeast chromosome XI. This gene encoded a serine-rich protein of 239 amino acids with a molecular weight of 24,267. The presence of hydrophobic sequences in the N- and C-termini of the CWP1 protein suggests that it is secreted as a glycosylphosphatidylinositol-anchored protein and is subsequently integrated into the cell wall. Since a gene disruption experiment showed no growth defect, the CWP1 gene is not essential for growth. Mutant CWP1 protein deficient in the C-terminal hydrophobic sequence was secreted into the culture medium, not anchored to the cell wall, thereby indicating that this hydrophobic sequence plays a crucial role in anchoring to the cell wall. Homology between the CWP1 protein and TIP1 family of cold shock proteins suggests that they belong to a new family of cell wall proteins.
一种分子量为40,000的酵母细胞壁糖蛋白，命名为gp40，通过与解纤维素生孢食纤维菌蛋白酶I（一种酵母裂解酶）孵育，从酿酒酵母的SDS提取细胞壁中溶解出来。基于其氨基酸序列，我们克隆并测序了编码gp40前体的基因，命名为CWP1；细胞壁蛋白基因。CWP1基因的DNA序列与YKL443相同，YKL443是在酵母XI号染色体基因组测序项目中鉴定出的一个开放阅读框。该基因编码一种富含丝氨酸的239个氨基酸的蛋白质，分子量为24,267。CWP1蛋白的N端和C端存在疏水序列，表明它作为糖基磷脂酰肌醇锚定蛋白分泌，随后整合到细胞壁中。由于基因破坏实验显示没有生长缺陷，CWP1基因对生长不是必需的。缺乏C端疏水序列的突变型CWP1蛋白分泌到培养基中，而不是锚定在细胞壁上，从而表明该疏水序列在锚定到细胞壁中起关键作用。CWP1蛋白与冷休克蛋白TIP1家族之间的同源性表明它们属于一个新的细胞壁蛋白家族。
