Transcription factor function of hairless

无毛的转录因子功能

• 批准号: 6744456
• 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/6744456
• 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）：最近在理解毛囊（HF）生物学方面取得了很多进展。 HF是一个动态结构，其多个隔室在生长过程（Anagen），回归（Catagen）和静息（端基（Telogen）（端基）阶段的过程中，多个隔室经历了复杂且高度同步的建筑重组的连续回合。已经在这些基因的突变中鉴定出了几种在正常头发周期中发挥作用的基因，包括无毛（HR），维生素D受体（VDR）和类维生素类动物X受体α（rxralpha）。在HR突变的情况下，在人类中引起小鼠和其他动物的脱发以及具有丘疹病变（APL，OMIM 209500）的卓越，HF结构的细胞和形态变化已经表征，但对HR突变中的分子机制却鲜为人知。尽管由HR基因（HR）编码的蛋白质的功能仍然未知，但几条证据表明HR是锌指类型的转录因子。 1）HR结构域与GATA-1锌指域具有同源性，该结构域负责DNA结合。 2）APL患者中的一个点突变导致甘氨酸取代了氨基酸的保守的，可能是锌协调的半胱氨酸残基622。3）HR突变导致功能性毛囊的完全joss，而4）HR局部局部局限于原子核。该建议旨在通过识别HR与HR结合的独特共识序列并分析该序列充当转录调节剂或无毛反应元件（HRE）的能力来证明HR实际上是锌指转录因子。前一个目标将通过随机的寡核苷酸选择和扩增来实现，该程序称为铸造。后一个目标将通过将任何假定的HRE纳入荧光素酶报告基因的启动子中，并在存在和不存在无毛的情况下分析各种构建体的转录活性。由于无毛表型与毛囊形态的变化有关，并且确定的一种可能的机制是异常的凋亡，因此，Homess功能的下游效应子可能是以组织特异性方式调节的广泛细胞周期基因的成员。分配无毛角色将是检查这些可能性的第一步。