论文部分内容阅读
P68蛋白是一种高度保守性的细胞核抗原,它对细胞生长和分裂具有重要的调节作用。在所有实验过的处于分裂期的哺乳和两栖类动物细胞中均能测出P68,而静止期细胞则无。该蛋白在核内呈独特的颗粒样分布,小鼠静止期成纤维细胞经血清刺激4h后能诱导P68表达。用抗SV40大T单克隆抗体PA6204鉴定表明:P68与DNA肿瘤病毒核癌基因SV40大T抗原具有免疫交叉反应性。实验从不同cDNA文库筛选P68蛋白的cDNA克隆,再亚克隆到M13上,然后用Sanger法测序,共测定了2088bp的DNA顺序,由此推测出P68蛋白的氨基酸顺序。与瑞士Prot数据库的其他蛋白质比较后发现:P68氨基酸顺序
The P68 protein is a highly conserved nuclear antigen that plays an important regulatory role in cell growth and division. P68 was detected in all experimental mammalian and amphibian cells at the stage of division, whereas resting cells were absent. The protein in the nucleus was a unique particle-like distribution, mouse quiescent fibroblasts stimulated by serum 4h after induction of P68 expression. Identification with anti-SV40 large T monoclonal antibody PA6204 showed that P68 was immunologically cross-reactive with the DNA tumor virus nuclear oncogene SV40 large T antigen. The cDNA clones of P68 were screened from different cDNA libraries and subcloned into M13, then sequenced by Sanger method. The DNA sequence of 2088bp was determined, and the amino acid sequence of P68 protein was deduced. Comparisons with other proteins in the Swiss Prot database revealed P68 amino acid sequence