Transcription factor function of hairless

无毛的转录因子功能

• 批准号: 6572665
• 负责人: ANDREW ENGELHARD
• 金额: $ 8.18万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6572665
• 关键词: DNA; apoptosis; binding sites; gene expression; gene mutation; genetic promoter element; genetic transcription; hair; hair follicle; histochemistry /cytochemistry; laboratory mouse; microarray technology; polymerase chain reaction; protein structure function; transcription factor

DESCRIPTION (provided by applicant): Recently much progress has been made in the understanding of hair follicle (HF) biology. The HF is a dynamic structure whose multiple compartments undergo successive rounds of complex and highly synchronized architectural reorganization during the growth (anagen), regression (catagen) and resting (telogen) phases of the hair cycle. Several genes that are thought to play a role in the catagen stage of the normal hair cycle, including hairless (hr), the vitamin D receptor (VDR), and the retinoid X receptor alpha (RXRalpha) have been identified on the basis of mutations in these genes which cause hair loss phenotypes. In the case of hr mutations, which cause alopecia in mice and other animals and atrichia with papular lesions (APL, OMIM 209500) in humans, cellular and morphologic changes in the structure of the HF have been characterized, yet little is known about the molecular mechanisms disrupted by hr mutations. Although the function of the protein coded by the hr gene (Hr) remains unknown, several lines of evidence suggest that Hr functions as a transcription factor of the zinc finger type. 1) An Hr domain shares homology with the GATA-1 zinc finger domain, which is responsible for DNA binding. 2) A point mutation in an APL patient results in the substitution of glycine for a conserved, presumably zinc-coordinating cysteine residue at amino acid 622. 3) Hr mutations result in the complete Joss of functional hair follicles, and 4) Hr localizes to the nucleus. This proposal aims to demonstrate that Hr is, in fact, a zinc finger transcription factor by identifying a unique consensus sequence to which Hr binds and by assaying the ability of this sequence to act as a transcriptional regulator or Hairless Responsive Element (HRE). The former aim will be accomplished through random oligonucleotide selection and amplification, a procedure known as CASTing. The latter aim will be accomplished by incorporating any presumed HREs into the promoter of luciferase reporter contructs and assaying transcriptional activity of various constructs in the presence and absence of hairless. Because the hairless phenotype is associated with changes in hair follicle morphology, and one possible mechanism identified is aberrant apoptosis, downstream effectors ofhaMess function might be members of a broad group of cell cycle genes regulated in a tissue-specific manner. The assignment of a role for hairless would be a first step in examining these possibilities.

描述(由申请人提供)：最近，在了解毛囊(HF)生物学方面取得了很大进展。HF是一种动态结构，其多个隔室在毛发周期的生长(生长期)、退化期(退化期)和静止期(休止期)经历了连续几轮复杂和高度同步的结构重组。根据导致脱发表型的基因突变，已确定了几个被认为在正常头发周期的退变阶段发挥作用的基因，包括无毛(Hr)、维生素D受体(VDR)和维甲酸X受体α(RXRpha)。在hr突变的情况下，它导致小鼠和其他动物的脱发，以及人类的丘疹皮损(APL，OMIM 209500)，已经表征了HF结构的细胞和形态变化，但对hr突变破坏的分子机制知之甚少。虽然HR基因编码的蛋白质的功能仍不清楚，但一些证据表明HR作为锌指类型的转录因子发挥作用。1)HR结构域与负责DNA结合的GATA-1锌指结构域有同源性。2)APL患者的点突变导致622位氨基酸的甘氨酸取代保守的、可能与锌配位的半胱氨酸残基。3)HR突变导致功能性毛囊完全JOS；4)HR定位于细胞核。这一建议旨在通过鉴定一个唯一的与HR结合的共识序列并分析该序列作为转录调控元件或无毛反应元件(HRE)的能力，来证明HR实际上是一个锌指转录因子。前一个目标将通过随机选择和扩增寡核苷酸来实现，这一过程被称为铸造。后一个目标将通过将任何假定的HRE整合到荧光素酶报告结构的启动子中，并在存在和不存在无毛的情况下分析各种结构的转录活性来实现。由于无毛表型与毛囊形态的变化有关，并且已发现的一个可能的机制是异常凋亡，因此HAMESS功能的下游效应因子可能是以组织特异性方式调节的一大组细胞周期基因的成员。为《无毛》分配一个角色将是考察这些可能性的第一步。