Perlman D, Raney P, Halvorson H O
Proc Natl Acad Sci U S A. 1986 Jul;83(14):5033-7. doi: 10.1073/pnas.83.14.5033.
Insertion mutations previously constructed within the proximal region of the yeast invertase signal sequence did not interfere with secretion or glycosylation of the enzyme. We now describe deletion mutations within the same signal sequence. Large deletions truncating the hydrophobic core of the signal peptide prevented both secretion and glycosylation of the enzyme and increased the intracellular concentration of nonglycosylated invertase. This increase was coupled with the appearance of a new invertase polypeptide, 2 kilodaltons larger than cytoplasmic invertase. The new polypeptide was consistent in size with uncleaved (signal peptide intact) pre-secretory invertase previously identified by using in vitro translation (apparent molecular mass, 62 kilodaltons). The data on enzyme activity indicate that invertase whose secretion is aborted by large deletion mutations augments the normal pool of cytoplasmic invertase found in sucrose-fermenting yeast cells.
先前构建在酵母转化酶信号序列近端区域内的插入突变并不影响该酶的分泌或糖基化。我们现在描述同一信号序列内的缺失突变。截断信号肽疏水核心的大片段缺失阻止了该酶的分泌和糖基化，并增加了非糖基化转化酶的细胞内浓度。这种增加伴随着一种新的转化酶多肽的出现，其比细胞质转化酶大2千道尔顿。新多肽的大小与先前通过体外翻译鉴定的未切割（信号肽完整）分泌前转化酶一致（表观分子量为62千道尔顿）。关于酶活性的数据表明，因大片段缺失突变而分泌受阻的转化酶增加了蔗糖发酵酵母细胞中正常的细胞质转化酶库。
