Regulation of gene expression by bHLHPAS protein transcriptional complexes

bHLHPAS 蛋白转录复合物对基因表达的调节

• 批准号: RGPIN-2018-05173
• 负责人: Beischlag, Timothy
• 金额: $ 4.66万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=757058
• 关键词: Regulation; gene; expression; bHLHPAS; protein

I am a molecular biologist with a desire to determine the molecular mechanisms of gene regulation by cellular multi-protein machines. We have characterized a transcriptional complex consisting of hypoxia-inducible factor1 (HIF), the aryl hydrocarbon receptor nuclear translocator (ARNT), the thyroid hormone receptor/retinoblastoma protein interacting protein-230 (TRIP230), and the retinoblastoma protein (Rb) involved in the regulation of specific sets of genes responsible for development, cellular transformation adaptation to low oxygen, and tissue damage. We have ablated Rb in human cell lines and found that genetic programs regulating tissue development, cellular motility and adaptive responses are sensitive to loss of Rb in a hypoxia-dependent fashion. A significant proportion of these genes are clustered on chromosomes suggesting that this complex regulates chromatin organization, thereby affecting specific genetic programs.I propose to expand our previous findings by focusing on how the hypoxia-inducible multi-protein complex regulates gene transcription and affects the outcomes of adaptive cellular responses and malignant transformation. Specifically, my short-term goal is to elucidate the means by which the hypoxia-inducible factor-/ (HIF1-ARNT) co-regulatory complex directs the expression of specific genetic programs and regulate chromatin organization. The specific aims of this proposal are;(1) To identify and characterize proteins mediating the HIF-ARNT_TRIP-Rb (HATR) complex activity. Factors recruited by Rb to attenuate the hypoxic response represent novel targets to manipulate genetic programs that regulate cell differentiation and adaptation to environmental stress. (2). To analyze long-term hypoxia-dependent gene silencing and de-repression after loss of Rb. Elucidation of the molecular mechanisms underlying Rb regulated HIF adaptive responses will enable us to identify malleable targets to remediate Rb loss. (3) To define the cistrome (DNA binding sites) of the HATR complex.This strategy will identify down-stream effectors of the biological responses regulated by the HATR complex and the manner in which it controls chromatin organization. These aims are novel in that they define a new role for a transcriptional complex known to be involved in the biology of cell development, adaptive responses to environmental stimuli and many pathological conditions. Following this strategy, we will in five years, have; (i) a realistic understanding of how the HATR complex directs specific genetic programs to regulate adaptive responses, and: (ii) identified protein targets regulating the HATR complex, its function and responses. These targets may be manipulated in the future to develop a more rational and targeted therapeutic approach to a number of pathologies including those involving cellular transformation.

我是一名分子生物学家，希望通过细胞多蛋白质机器来确定基因调控的分子机制。我们已经确定了一个由低氧诱导因子1(HIF)、芳香烃受体核转运子(ARNT)、甲状腺激素受体/视网膜母细胞瘤蛋白相互作用蛋白-230(TRIP230)和视网膜母细胞瘤蛋白(RB)组成的转录复合体，该转录复合体参与调控一组特定的基因，这些基因参与了发育、细胞对低氧的转化适应和组织损伤。我们已经切除了人类细胞系中的Rb，并发现调控组织发育、细胞运动和适应性反应的遗传程序对Rb的丢失非常敏感，这种丢失依赖于低氧。这些基因中有很大一部分聚集在染色体上，这表明这种复合体调节染色质组织，从而影响特定的遗传程序。我建议通过关注低氧诱导的多蛋白复合体如何调节基因转录并影响适应性细胞反应和恶性转化的结果来扩展我们之前的发现。具体地说，我的短期目标是阐明低氧诱导因子-/(HIF1-Arnt)共调控复合体如何指导特定遗传程序的表达和调节染色质组织。该建议的具体目的是：(1)鉴定和鉴定介导HIF-Arnt_Trip-Rb(HATR)复合体活性的蛋白质。RB招募的减弱低氧反应的因子代表着操纵调节细胞分化和对环境压力适应的遗传程序的新靶点。(2)。分析Rb缺失后长期低氧依赖的基因沉默和下调。阐明Rb调节的HIF适应性反应的分子机制将使我们能够识别可延展的靶点来补救Rb的丢失。(3)确定HATR复合体的cstrome(DNA结合位点)。这一策略将确定HatR复合体调控的生物反应的下游效应物及其控制染色质组织的方式。这些目的是新颖的，因为它们定义了一个已知的转录复合体的新角色，该复合体涉及细胞发育的生物学、对环境刺激的适应性反应和许多病理条件。按照这一战略，我们将在五年内：(I)现实地了解HATR复合体如何指导特定的遗传程序来调节适应性反应，以及(Ii)确定调节HatR复合体的蛋白质靶标、其功能和响应。这些靶点可能会在未来被操纵，以开发一种更合理和更有针对性的治疗方法来治疗包括细胞转化在内的许多病理疾病。