LaMantia M, Miura T, Tachikawa H, Kaplan H A, Lennarz W J, Mizunaga T
Department of Biochemistry and Cell Biology, State University of New York, Stony Brook 11794-5215.
Proc Natl Acad Sci U S A. 1991 May 15;88(10):4453-7. doi: 10.1073/pnas.88.10.4453.
Glycosylation site binding protein (GSBP) has been shown to be identical to protein disulfide isomerase (PDI; EC 5.3.4.1) in a variety of multicellular organisms. We have utilized immunological and biochemical techniques to determine if GSBP and PDI are identical in yeast. Antiserum prepared against yeast GSBP identified in microsomes by its ability to be labeled with a peptide photoaffinity probe was found to recognize PDI purified from yeast. Moreover, this purified yeast PDI was found to be specifically labeled by the photoaffinity probe originally used to identify GSBP in a variety of eukaryotes. On the basis of these observations, we conclude that yeast GSBP and PDI are the same protein. The structure of the yeast PDI gene revealed a product with sequence similarity to higher eukaryotic PDI/GSBP. Disruption of this gene in yeast resulted in a recessive lethal mutation, indicating that PDI/GSBP is required for cell viability.
在多种多细胞生物中，糖基化位点结合蛋白（GSBP）已被证明与蛋白二硫键异构酶（PDI；EC 5.3.4.1）相同。我们利用免疫学和生化技术来确定酵母中的GSBP和PDI是否相同。通过其被肽光亲和探针标记的能力在微粒体中鉴定出的针对酵母GSBP制备的抗血清，被发现能识别从酵母中纯化的PDI。此外，发现这种纯化的酵母PDI被最初用于在多种真核生物中鉴定GSBP的光亲和探针特异性标记。基于这些观察结果，我们得出结论，酵母GSBP和PDI是同一种蛋白质。酵母PDI基因的结构揭示了一种与高等真核生物PDI/GSBP具有序列相似性的产物。酵母中该基因的破坏导致隐性致死突变，表明PDI/GSBP是细胞活力所必需的。
