Structural studies of biomolecules related to cancer and HIV-AIDS

与癌症和艾滋病相关的生物分子的结构研究

• 批准号: 10926649
• 负责人: Hiroshi Matsuo
• 金额: $ 65.5万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10926649
• 关键词: APOCEC3G gene; Affinity; Binding; Catalytic Domain; Cells; Complex; Conflict (Psychology); Cryoelectron Microscopy; Cytosine deaminase; DNA; DNA Sequence Alteration; Deamination; Defense Mechanisms; Epitopes; Evolution; Goals; HIV Genome; HIV-1; HIV/AIDS; Human; Infection; Magnetism; Malignant Neoplasms; Modification; Mutate; Mutation; Nuclear; Nucleotides; Pathway interactions; Prognosis; Proteins; RNA; Reaction; Research; Research Project Grants; Role; Single-Stranded DNA; Source; Spectrum Analysis; Structure; Techniques; Testing; Ubiquitin; Virion; X-Ray Crystallography; Zebularine; analog; cancer therapy; cancer type; inhibitor; multicatalytic endopeptidase complex; novel therapeutics; pathogen; protein structure; response; therapy resistant; tumor; tumor growth; tumor progression; ubiquitin-protein ligase

APOBEC3G (A3G) and APOBEC3H (A3H) are single-stranded DNA cytosine deaminase that can restrict HIV-1 infection by mutating HIV-1 genome. HIV-1 developed a counter defense mechanism by which virion infectivity factor (Vif) leads the degradation of A3G/A3H through ubiquitin-proteasome pathway. Our ultimate goal is to generate small compounds which inhibit the degradation of A3G/A3H. Previously, we had determined NMR and crystal structures of domains of A3 proteins, including the VIf-binding domain and the catalytic domain. In addition, we had determined co-crystal structures of the A3's catalytic domain-ssDNA complex. We have obtained cryo-EM structure of APOBEC3G:HIV-1 Vif complex which provided unique A3G-RNA and Vif-RNA interaction in addition to A3G-Vif interaction (Kouno et al., Nat. Commun. 2023). We have made progress in determining the structure of the A3H-Vif E3 ubiquitin ligase complex by using cryoEM, which will provide epitopes to be targeted by small compounds which inhibit formation of the complex. Dysregulation of APOBEC3A (A3A) and APOBEC3B (A3B) proteins contributes a major endogenous source of DNA mutations traced in approximately 75% of cancer types and 50% of all cancers analyzed. A3A/A3B proteins can cause DNA mutations either alone or as the response to cancer therapies which can drive evolution of cancers, and A3A/A3B related mutations maybe associated with poor prognosis and therapeutic resistance in cancers. We have determined co-crystal structure of the A3G-catalytic domain and 2'-deoxy-zebularine DNA and reveal a transition state of deamination. We are developing ssDNA based A3A/A3B inhibitors as ssDNA is the natural substrate for their catalytic reaction. A transition state analogue, 2'-deoxy-zebularine, was incorporated into the target ssDNA sequence of A3A/A3B, and yielded promising affinity and inhibitory effect. We are currently testing modification of nucleotides in order to resist degradation in cells.

APOBEC3G (A3G) 和 APOBEC3H (A3H) 是单链 DNA 胞嘧啶脱氨酶，可以通过突变 HIV-1 基因组来限制 HIV-1 感染。 HIV-1 形成了一种反防御机制，病毒粒子感染因子 (Vif) 通过泛素蛋白酶体途径导致 A3G/A3H 降解。我们的最终目标是产生抑制 A3G/A3H 降解的小化合物。此前，我们已经确定了 A3 蛋白结构域的 NMR 和晶体结构，包括 VIf 结合结构域和催化结构域。此外，我们还确定了 A3 催化结构域-ssDNA 复合物的共晶结构。我们获得了 APOBEC3G:HIV-1 Vif 复合物的冷冻电镜结构，除了 A3G-Vif 相互作用之外，该复合物还提供独特的 A3G-RNA 和 Vif-RNA 相互作用（Kouno 等人，Nat. Commun. 2023）。我们在使用冷冻电镜确定 A3H-Vif E3 泛素连接酶复合物的结构方面取得了进展，这将提供抑制复合物形成的小化合物靶向的表位。 APOBEC3A (A3A) 和 APOBEC3B (A3B) 蛋白的失调是约 75% 的癌症类型和 50% 的所有分析癌症中 DNA 突变的主要内源来源。 A3A/A3B 蛋白可以单独引起 DNA 突变，也可以作为对癌症治疗的反应，从而推动癌症的进化，并且 A3A/A3B 相关突变可能与癌症的不良预后和治疗耐药性有关。我们确定了 A3G 催化结构域和 2'-脱氧-zebularine DNA 的共晶结构，并揭示了脱氨的过渡态。我们正在开发基于 ssDNA 的 A3A/A3B 抑制剂，因为 ssDNA 是其催化反应的天然底物。将过渡态类似物 2'-deoxy-zebularine 整合到 A3A/A3B 的靶 ssDNA 序列中，并产生了良好的亲和力和抑制作用。我们目前正在测试核苷酸的修饰，以抵抗细胞中的降解。