Evaluation systems for individual sensitivity against ultraviolet light using one hair alone

这个项目的目的是设计一种系统，通过测量酪氨酸酶或修复基因的转录表达来监测个体对紫外线的敏感性，已知这种基因可以防御紫外线辐射的有害影响。1)小鼠酪氨酸酶基因的5‘上游调节区包含一个长的(GA)n序列，它可能能够采用三螺旋构象(Triplex)。结果表明，小鼠酪氨酸酶转录本的3‘非编码RNA片段在转录水平上抑制了自身的表达。这可能是通过阻止细胞类型特异性蛋白因子(S)与基因5‘上游区域的调控顺式元件结合，可能是通过三链形成。2)酪氨酸酶是合成黑色素的关键酶，它主要决定哺乳动物的皮肤颜色。我们通过产生转基因小鼠，提供了非哺乳动物基因的5‘侧翼序列在体内具有功能的证据。3)小眼症--ASSOC…更相关的转录因子(MITF)在神经沟来源的黑素细胞和视杯来源的视网膜色素上皮(RPE)的发育中起着关键作用。我们发现，黑素细胞的发育严重依赖于单一的MITF亚型MITF-M。4)我们建立了一种原位杂交技术来检测阿片黑素皮质素原、酪氨酸酶、酪氨酸酶相关蛋白-1、多巴色素互变异构酶、P-蛋白、PMEL-17/gp100和小眼球相关转录因子的mRNA水平。结果表明，人类皮肤的晒黑反应机制可能涉及某些色素基因的转录调控。5)利用一种检测紫外线损伤的抗体和一种抗UvrA抗体，检测了大肠杆菌recA株的修复能力。我们的结果表明，RecA细胞中UvrA蛋白的构成水平导致活性UvrABC核酸酶的构成水平不足以进行全核苷酸切除修复(NER)，从而导致极端的紫外线敏感性。较少

This project has been intended to devise system that can monitor individual UV sensitivity by measuring transcriptional expression of tyrosinase or repair genes, which is known to defend from the deleterious effects of UV radiation.1) The 5' upstream regulatory region of the mouse tyrosinase gene contains a long (GA)n sequence, that may be capable adopting a triple-helical conformation (triplex). The results suggest that the 3'non-coding RNA fragments of mouse tyrosinase transcripts suppress its own expression at the transcriptional level. This might occur by preventing cell type-specific protein factor(s) from binding to the regulatory cis-elements in the 5' upstream region of the gene, possibly through a triplex formation.2) Tyrosinase is the key enzyme for synthesizing melanin pigments, which primarily determine mammalian skin coloration. We provide evidence that 5'flanking sequences from nonmammalian genes are functional in vivo by producing transgenic mice. 3) Microphthalmia-assoc … More iated transcription factor (MITF) plays a critical role in the development of both neural-crest-derived melanocytes and optic cup-derived retinal pigmented epithelium (RPE). We found that melanocyte development depends critically on a single Mitf isoform, Mitf-M. 4) We have established an in situ hybridization technique to investigate mRNA levels of pro-opiomelanocortin, tyrosinase, tyrosinase-related protein-1, dopachrome tautomerase, P-protein, Pmel-17/gp100, and microphthalmia-associated transcription factor. Results suggest that the mechanism of the tanning response of human skin may involve the transcriptional regulation of certain pigmentary genes. 5) Using an antibody to detect UV damage and anti-UvrA antibody, we measured the repair ability of recA strain of E. coli. Our results indicate that constitutive level of UvrA protein in the recA cells results in constitutive levels of active UvrABC nuclease which is not enough to operate full nucleotide excision repair (NER), thus leading to extreme UV sensitivity. Less