A bipartite nuclear localization signal in the retinoblastoma gene product and its importance for biological activity
A bipartite nuclear localization signal in the retinoblastoma gene product and its importance for biological activity
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视网膜母细胞瘤基因产物中的二分核定位信号及其对生物活性的重要性
DOI：
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发表时间：
1993
影响因子：
5.3
通讯作者：
B. Gallie
中科院分区：
文献类型：
--
作者：
E. Zacksenhaus;R. Bremner;R. A. Phillips;B. Gallie
视网膜母细胞瘤基因产物p110RB1似乎通过调节核转录因子的活性来调节细胞生长。指定p110RB1转运到细胞核的元素尚未被探索。我们现在报道在p110RB1的C端鉴定了一个基本区域KRSAEGGNPPKPLKKLR，该区域与已知的双部核定位信号（nnlss）具有序列相似性。在这个假定的NLS中引入两个氨基酸的突变[产生突变的NLS(NQ)]或删除整个NLS（delta NLS）取消了排他的核定位，产生的蛋白质要么均匀分布在整个细胞中，要么主要分布在细胞质中。一种突变蛋白[NLS(NQ)/delta 22]包含突变的NLS和外显子22的缺失，先前被证明可以破坏p110RB1与几种细胞转录因子和癌蛋白的相互作用，仅在细胞质中积累。当RB1 NLS融合到大肠杆菌β -半乳糖苷酶的C端时，RB1 NLS将该蛋白定向到细胞核，这表明该基序不仅是核运输的必要条件，而且是充分条件。NLS（NQ）和delta NLS在体内都没有过度磷酸化，但在体外都保留了与猿猴病毒40大T抗原、腺病毒E1a和细胞转录因子E2F相互作用的能力。当转染多个拷贝数时，NLS突变等位基因表现出生物活性降低，通过抑制成骨肉瘤细胞系Saos-2的生长来测量，该细胞系没有野生型RB1。破坏NLS的RB1外显子25自然发生的突变和缺失可能导致p110RB1部分或完全失活，并可能导致一些视网膜母细胞瘤和其他肿瘤。
The retinoblastoma gene product, p110RB1, appears to regulate cell growth by modulating the activities of nuclear transcription factors. The elements that specify the transport of p110RB1 into the nucleus have not yet been explored. We now report the identification of a basic region, KRSAEGGNPPKPLKKLR, in the C terminus of p110RB1, which has sequence similarity to known bipartite nuclear localization signals (NLSs). A two-amino-acid mutation introduced into this putative NLS [to give mutant NLS(NQ)] or deletion of the entire NLS (delta NLS) abrogated exclusive nuclear localization, yielding proteins which were distributed either equally throughout the cell or predominantly in the cytoplasm. A mutant protein [NLS(NQ)/delta 22] containing both the mutated NLS and a deletion of exon 22, previously shown to disrupt the interaction of p110RB1 with several cellular transcription factors and oncoproteins, accumulated only in the cytoplasm. When fused to the C terminus of Escherichia coli beta-galactosidase, the RB1 NLS directed this protein to the nucleus, indicating that the motif is not only necessary but also sufficient for nuclear transport. Neither NLS(NQ) nor delta NLS was hyperphosphorylated in vivo, but both retained their abilities to interact, in vitro, with simian virus 40 large T antigen, adenovirus E1a, and the cellular transcription factor E2F. When transfected at multiple copy number, the NLS mutant alleles displayed reduced biological activity, measured by inhibition of growth of the osteogenic sarcoma cell line Saos-2, which has no wild-type RB1. Naturally occurring mutations and deletions in exon 25 of RB1 which disrupt the NLS may lead to partial or complete inactivation of p110RB1 and may be responsible for some retinoblastoma and other tumors.
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影响因子：
56.9
作者：
HUANG, HJS;YEE, JK;LEE, WH
通讯作者：
LEE, WH
视网膜母细胞瘤蛋白的亚细胞定位。
DOI：
--
发表时间：
1991
期刊：
Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research
影响因子：
--
作者：
Szekely,L;Uzvolgyi,E;Jiang,WQ;Durko,M;Wiman,KG;Klein,G;Sumegi,J
通讯作者：
Sumegi,J
DOI：
10.1073/pnas.86.17.6474
发表时间：
1989-09-01
影响因子：
11.1
作者：
BERNARDS, R;SCHACKLEFORD, GM;WEINBERG, RA
通讯作者：
WEINBERG, RA
影响因子：
56.9
作者：
DYSON, N;HOWLEY, PM;HARLOW, E
通讯作者：
HARLOW, E
使用产生 N 末端截短的大 T 抗原的 SV40 突变体，将 Rb 结合和不依赖锚定的生长与永生化和致瘤性分离。
影响因子：
3.7
作者：
Thompson,DL;Kalderon,D;Smith,AE;Tevethia,MJ
通讯作者：
Tevethia,MJ