Yeast Gaa1p is required for attachment of a completed GPI anchor onto proteins.
Yeast Gaa1p is required for attachment of a completed GPI anchor onto proteins.
复制标题
将完整的GPI锚固固定在蛋白质上需要酵母GAA1P。
DOI：
10.1083/jcb.129.3.629
复制
发表时间：
1995-05
期刊：
影响因子：
--
通讯作者：
Riezman H
中科院分区：
文献类型：
--
作者：
Hamburger D;Egerton M;Riezman H
糖基磷脂酰肌醇（GPIs）将蛋白质固定在细胞膜上是所有真核生物中普遍存在的，也被寄生原生动物大量使用。GPI被合成并整体转移以形成GPI锚定蛋白。该过程中的关键酶是假定的GPI：蛋白质转酰胺酶，其将切割蛋白质的COOH末端附近的肽键并通过酰胺键连接GPI。我们已经确定了一个基因，GAA1，编码GPI锚定所需的必需ER蛋白。gaal突变细胞在非允许温度下合成完整的GPI锚前体，但不将其附着到蛋白质上。GAA1的过表达提高了细胞将锚附着到具有突变锚附着位点的GPI锚定蛋白的能力。因此，Gaa1 p是GPI锚附着的末端步骤所必需的，并且可能是推定的GPI：蛋白质转酰胺酶的一部分。
Anchoring of proteins to membranes by glycosylphosphatidylinositols (GPIs) is ubiquitous among all eukaryotes and heavily used by parasitic protozoa. GPI is synthesized and transferred en bloc to form GPI- anchored proteins. The key enzyme in this process is a putative GPI:protein transamidase that would cleave a peptide bond near the COOH terminus of the protein and attach the GPI by an amide linkage. We have identified a gene, GAA1, encoding an essential ER protein required for GPI anchoring. gaal mutant cells synthesize the complete GPI anchor precursor at nonpermissive temperatures, but do not attach it to proteins. Overexpression of GAA1 improves the ability of cells to attach anchors to a GPI-anchored protein with a mutant anchor attachment site. Therefore, Gaa1p is required for a terminal step of GPI anchor attachment and could be part of the putative GPI:protein transamidase.