PURIFICATION OF A RAN-INTERACTING PROTEIN THAT IS REQUIRED FOR PROTEIN IMPORT INTO THE NUCLEUS
PURIFICATION OF A RAN-INTERACTING PROTEIN THAT IS REQUIRED FOR PROTEIN IMPORT INTO THE NUCLEUS
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DOI：
10.1073/pnas.91.21.10212
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发表时间：
1994-10-11
影响因子：
11.1
通讯作者：
BLOBEL, G
中科院分区：
文献类型：
--
作者：
MOORE, MS;BLOBEL, G
以前，我们报道了分离的两个胞质组分（A和B）从非洲爪蟾卵巢所需的顺序，以支持毛地黄皂苷透化细胞的细胞核的蛋白质进口。部分A是识别核定位序列和靶向核膜所需的，而部分B是随后将结合的底物易位到核中所需的。纯化组分B活性所需的第一种蛋白质是小GTdR an（ras相关核蛋白）。在这里，我们报告的第二个（和最终）的蛋白质的纯化所需的馏分B的活动。通过SDS/PAGE，纯化的蛋白质表现为具有10 kDa的表观分子量的单一条带，但天然蛋白质在凝胶过滤色谱上分级分离，具有30 kDa的表观大小。肽序列分析表明，纯化的蛋白质是高度同源的一个以前确定的未知功能的人类蛋白质称为胎盘蛋白15（pp 15）和预测的蛋白质产物的酵母开放阅读框架从酿酒酵母。
Previously we reported the isolation of two cytosolic fractions (A and B) from Xenopus ovary that are required sequentially to support protein import into the nuclei of digitonin-permeabilized cells. Fraction A is required for recognition of the nuclear localization sequence and targeting to the nuclear envelope, whereas fraction B is required for the subsequent translocation of the bound substrate into the nucleus. The first protein required for fraction B activity to be purified was the small GTPase Ran (ras-related nuclear protein). Here we report the purification of the second (and final) protein required for fraction B activity. By SDS/PAGE, the purified protein appeared as a single band with an apparent molecular mass of 10 kDa, but the native protein fractionated upon gel filtration chromatography with an apparent size of 30 kDa. Peptide sequence analysis indicated that the purified protein was highly homologous to a previously identified human protein of unknown function called placental protein 15 (pp15) and to the predicted protein product of a yeast open reading frame from Saccharomyces cerevisiae.