Structural and Functional Characterization of BRCA1/BARD1

BRCA1/BARD1 的结构和功能表征

• 批准号: 7931268
• 负责人: Rachel E Klevit
• 金额: $ 19.83万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7931268
• 关键词: Affinity; Ankyrin Repeat; BARD1 gene; BRCA1 gene; Binding; Binding Proteins; Biochemical; Biological; Biological Assay; Breast; C-terminal; Cell physiology; Cells; Chromosome abnormality; Complex; Crystallography; DNA Damage; Enzymes; Estrogen Receptors; Estrogens; Event; Functional disorder; Future; Genes; Genome Stability; Goals; Grant; Health; Human; Human Ubiquitin; In Vitro; Inherited; Investigation; Knock-in Mouse; Knock-out; Lead; Learning; Ligase; Link; Maintenance; Malignant Neoplasms; Malignant neoplasm of ovary; Mass Spectrum Analysis; Methods; Molecular; Mono-S; Multienzyme Complexes; Mus; Mutation; N-terminal; Nature; Outcome; Play; Polyubiquitin; Progesterone Receptors; Protein Binding; Proteins; Regulation; Resolution; Role; Substrate Interaction; System; TP53 gene; Techniques; Testing; Tumor Suppressor Proteins; Ubiquitin; Ubiquitin-Conjugating Enzymes; Ubiquitination; Woman; Work; Yeasts; in vivo; insight; lifetime risk; malignant breast neoplasm; mutant; protein complex; public health relevance; research study; response; three dimensional structure; tool; ubiquitin ligase; ubiquitin-protein ligase; yeast two hybrid system

DESCRIPTION (provided by applicant): The breast and ovarian cancer tumor suppressor protein, BRCA1, and its obligate protein partner, BARD1 are critical to proper functioning of fundamental cellular processes that support genomic stability. To date, a single biochemical activity has been identified for BRCA1/BARD1, namely, they function together as a ubiquitin E3 ligase. Although it is believed that the ability of BRCA1/BARD1 to modify specific cellular proteins with ubiquitin is fundamental to its role as a tumor suppressor, the details and ramifications of this relationship remain to be elucidated. During the past grant period, we discovered that BRCA1/BARD1 can function with ten human ubiquitin-conjugating enzymes (E2s) and that the ultimate product generated by BRCA1/BARD1 on substrates depends on the E2 present. We also identified several new substrates, including the estrogen receptor. In the next grant period we will expand our focus to include the essential subunit, BARD1, more explicitly and will participate in a collaborative effort to develop new molecular insights and tools for another RING E3 ligase that is critical in cancers, Mdm2/MdmX. The overall goals for the next grant period are 1) elucidate structural and functional determinants of mono-ubiquitin transfer and poly-ubiquitin chain formation by BRCA1/BARD1 and its interacting E2s, 2) investigate the molecular and structural determinants of BRCA1/BARD1-substrate interactions, 3) characterize BARD1 and its interactions, and 4) identify the human E2s that interact with Mdm2/MdmX, the ligase responsible for p53 regulation in vivo. A broad experimental approach will be undertaken, including biochemical, structural, molecular biological, and cellular techniques. Results from these studies will provide new insights into BRCA1/BARD1 function and will contribute to the general understanding of protein ubiquitination. PUBLIC HEALTH RELEVANCE: The breast and ovarian cancer tumor suppressor protein, BRCA1, plays a role in the maintenance of genomic stability and its loss or dysfunction leads to widespread chromosomal abnormalities. Inheritance of a mutant form of BRCA1 increases a woman's lifetime risk of developing breast cancer from 1 in 8 to greater than 1 in 2. Some of the most common inherited mutations abrogate BRCA1's function as a ubiquitin ligase, implying that this function is central to the health of a cell. A full description of the molecular interactions that are critical to BRCA1 function will provide new insight into the early events associated with loss of BRCA1 that lead to tumorogenesis.

描述（由申请人提供）：乳腺癌和卵巢癌肿瘤抑制蛋白BRCA 1及其专性蛋白伴侣BARD 1对支持基因组稳定性的基本细胞过程的正常功能至关重要。迄今为止，已经鉴定了BRCA 1/BARD 1的单一生物化学活性，即它们作为泛素E3连接酶一起起作用。尽管人们认为BRCA 1/BARD 1用泛素修饰特定细胞蛋白的能力是其作为肿瘤抑制因子的基础，但这种关系的细节和分支仍有待阐明。在过去的资助期间，我们发现BRCA 1/BARD 1可以与10种人泛素结合酶（E2）一起发挥作用，并且BRCA 1/BARD 1在底物上产生的最终产物取决于E2的存在。我们还发现了几种新的底物，包括雌激素受体。在下一个资助期内，我们将扩大我们的重点，更明确地包括基本亚基BARD 1，并将参与合作努力，为另一种在癌症中至关重要的RING E3连接酶Mdm 2/MdmX开发新的分子见解和工具。下一个资助期的总体目标是：1）阐明BRCA 1/BARD 1及其相互作用E2的单泛素转移和多泛素链形成的结构和功能决定因素，2）研究BRCA 1/BARD 1-底物相互作用的分子和结构决定因素，3）表征BARD 1及其相互作用，4）鉴定与Mdm 2/MdmX相互作用的人E2。负责体内p53调节的连接酶。将采取广泛的实验方法，包括生物化学，结构，分子生物学和细胞技术。这些研究的结果将为BRCA 1/BARD 1功能提供新的见解，并将有助于对蛋白质遍在化的全面了解。公共卫生相关性：乳腺癌和卵巢癌肿瘤抑制蛋白BRCA 1在维持基因组稳定性方面发挥作用，其缺失或功能障碍导致广泛的染色体异常。BRCA 1突变形式的遗传增加了女性一生中患乳腺癌的风险，从1/8增加到1/2以上。一些最常见的遗传突变废除了BRCA 1作为泛素连接酶的功能，这意味着这种功能对细胞的健康至关重要。对BRCA 1功能至关重要的分子相互作用的完整描述将为与导致肿瘤发生的BRCA 1缺失相关的早期事件提供新的见解。