【作者】 彭瀚；

【导师】 张俊武；

【作者基本信息】 中国协和医科大学 ， 生化与分子生物学， 2006， 博士

【摘要】 造血是人一生中不断由多能造血干细胞更新造血祖细胞和成熟血细胞的过程。现在认为造血干细胞分化定向到某一个特定血细胞链系以及进一步分化发育为成熟细胞的过程至少部分地是由链系特异的转录因子和广泛表达的转录因子协同作用所控制。一些包含C2H2锌指模体的转录因子在血细胞的分化和发育过程中扮演了重要角色。例如GATA家族、FOG和EKLF等。 我组2000年从人骨髓cDNA文库中筛选到一个新的编码锌指蛋白(命名为HZF1)的cDNA(GenBank注册号：AF244088)。本论文在此基础上研究HZF1基因结构、表达、功能和作用机制。 对hemin诱导的K562细胞中获得的cDNA进行PCR扩增，鉴别到HZF1基因的3种转录物，它们可能由HZF1初级转录物不同的剪接产生。分析发现HZF1基因包含四个外显子和三个内含子。其中一个转录物包含第3、4号外显子，第二个包含第1、3、4号外显子，第三个转录物包含有全部4个外显子。这三种转录物的序列差异仅在5’非翻译区，因此编码的肽链是一致的。HZF1编码区长2010bp，编码670个氨基酸残基，其中包含连续的15个C2H2型和2个C2R2型锌指模体。 HZF1 mRNA在人的脑、心、骨骼肌、肾、肝、胰腺和胎肝中高表达；在脾、小肠和骨髓组织中等表达；在结肠、胸腺、肺和外周血白血病中少量表达。HZF1mRNA在各种造血细胞系中都有表达。在hemin诱导K562细胞向红系分化过程中HZF1 mRNA表达上调，诱导24h后HZF1 mRNA表达水平到达最高。同样，在PMA诱导K562细胞向巨核系分化过程中HZF1 mRNA表达上升，诱导60h后表达水平达到峰值。 把HZF1完整读框插入到pEGFP-N1质粒中，构建真核表达载体oEGFP-N1-HZF1，转染NIH3T3细胞，48小时后在荧光显微镜下观察，发现HZF1融合蛋白定位在细胞核中。更多还原

【Abstract】 Hematopoiesis is a lifelong process responsible for replenishing hematopoietic progenitor cells and mature blood cells from a pool of pluripotent, long-term reconstituting stem cells. Commitment of stem cells to specific hematopoietic lineages and further differentiation and development mature of the committed cells are controlled at least partially through the combinatorial action of lineage-restricted and more widely expressed transcription factors. Some transcription factors containing C2H2 zinc finger motif, such as GATA family, FOG, and EKLF, have been found to play an important part in differentiation and development of blood cells.In 2000, we cloned a novel zinc finger cDNA HZF1 (GenBank accession No. AF244088) by screening a human bone marrow cDNA library. Based on that, my works focused on the research of the HZF1 gene construct, expression, functions and the molecular mechanism of HZF1 functions.Three different transcripts of HZF1 gene were identified by PCR amplification of cDNAs derived from hemin-induced K562 cells, which may result from different splicing of pre-mRNA of HZF1 gene. HZF1 gene contains four exons and three introns. One transcript contains exon 3 and 4, the second contains exons 1, 3 and 4 and the third contains all four exons. The encoded peptide should be identical because the differences among them are only involved in 5’ non-translation region of HZF1 mRNA. The HZF1-coding sequence is 2010bp and the putative protein consists of 670 amino acid residues including 15 typical C2H2 and 2 C2RH zinc finger motifs.HZF1 mRNA expression was detected in ubiquitous tissues. The HZF1 mRNA was expressed highly in brain, heart, skeletal muscle, kidney, liver, placenta and fetal liver, moderately in spleen, small intestine and bone marrow, and slightly in colon, thymus,更多还原