【作者】 胡翔；

【导师】 张健； 周建林；

【作者基本信息】 湖南师范大学 ， 生物化学及分子生物学， 2003， 硕士

【摘要】 PDIP1(polymerase delta-interacting protein 1)基因是在人HepG2细胞中克隆的一个基因。初步证实了PDIP1基因能与DNA聚合酶δ的小亚基p50和辅助蛋白PCNA相互作用。因此推测，PDIP1蛋白可能部分协助或参与DNA的复制和修复。此外，通过BLAST检索发现PDIP1蛋白与一个受TNF-α诱导的蛋白质B12十分相似，彼此的氨基酸序列高达70％是相同的。因此，推测PDIP1蛋白质可能与之有相似的生物功能。TNF-α是由激活的巨噬细胞产生的细胞激活素，能诱导细胞凋亡，特别是对肿瘤细胞。而B12在细胞凋亡过程中也有一定的作用。因此，PDIP1可能在细胞凋亡中也起到一定的作用。TNF-α的另一个重要功能是在肝脏受伤后启动肝脏再生。因此PDIP1基因也可能在肝脏再生过程中有一定的功能。 为了进一步研究PDIP1基因对细胞凋亡、肝脏再生的作用，我们首先采用RACE PCR的方法克隆了小鼠PDIP1基因的cDNA全长。小鼠PDIP1基因cDNA全长为1677bp，编码329个氨基酸残基。通过生物信息学分析，我们得知小鼠PDIP1基因位于7号染色体的F3位点上，可能是一个转录因子在细胞核内发挥生物功能。并且得知哺乳动物体内存在一个PDIP1基因家族，此家族至少含有三个基因，分别命名为PDIP1-α、PDIP1-β、PDIP1-γ。我们设计合适的探针，采用核酸酶保护反应等技术测定了PDIP1-α基因在肝脏部分切除后不同时间在小鼠肝脏中的表达，发现PDIP1-α基因在肝脏部分切除后表达增强，12小时表达最强，以后表达减弱。初步表明该基因对肝脏损伤后的修复与再生有关。更多还原

【Abstract】 Polymerase delta-interacting protein 1 (PDIP1) gene was cloned in human HepG2 cells. The interaction of PDIPl with the small subunit (p50) of DNA polymerase δ ( pol δ ) and the proliferating cell nuclear antigen(PCNA) was confirmed, suggesting that PDIPl may partly assist or participate in the DNA replication and/or repair. Homology searches using BLAST with the amino acid sequence revealed that PDIPl shares a high degree of homology (70% identity) with the TNF-α induced protein B12. So PDIPl may have similar biological function as B12. TNF- α , a cell cytokine produced by the macrophage cells has a function of inducing apoptosis, especially for the tumor cells. This finding suggests that PDIPl may play a partial role in apoptosis, because B12 also has this function. Another important function of THF-α is to initiate liver regeneration after the liver was damaged. Therefore, the PDIPl gene may also play a role in liver regeneration.To further study the function of PDIPl in apoptosis and liver regeneration, we cloned the full length cDNA of mouse PDIPl by RACE PCR. The full length cDNA has 1677 bp and encodes a polypeptide of 329 amino acids. Through bioinformatic analysis, we know that the PDIPl gene was mapped to mouse chromosome 7 at F3. PDIP1 may be a transcription factor functioning in the cell nucleus. We also found that there is a PDIPl gene family including at least 3 genes. We named them as PDIPl- α ,PDIPl- β ,PDIPl-γ . We designed a suitable probe in the experiment and used Ribonuclease protection assay technology to detect the expression of PDIPl gene in mouse liver at different time points after partial hepatectomy. We found that the expression of PDIPl gene was increased. It reached the highest level after 12 hours and then decreased. Our data suggest that PDIPl gene may play a role in the repair and regeneration of damaged livers.更多还原