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开发了一种反式机制，通过该机制，病毒体感染因子（VIF）通过泛素 - 蛋白酶体途径导致A3G/A3H的降解。我们的最终目标是生成抑制A3G/A3H降解的小化合物。以前，我们已经确定了A3蛋白域的NMR和晶体结构，包括VIF结合域和催化域。此外，我们确定了A3催化结构域-SSDNA复合物的共结晶结构。我们还获得了APOBEC3G：HIV-1 VIF复合物的冷冻EM结构，该复合物除A3G-VIF相互作用外提供了独特的A3G-RNA和VIF-RNA相互作用（Kouno等，Nat。Commun。2023）。我们通过使用Cryoem来确定A3H-VIF E3泛素连接酶复合物的结构取得了进展，这将提供由抑制复合物形成的小化合物靶向的表位。 APOBEC3A（A3A）和APOBEC3B（A3B）蛋白的失调贡献了大约75％的癌症类型的DNA突变的主要内源性来源，所有分析的癌症的50％。 A3A/A3B蛋白可以单独引起DNA突变，也可以作为对癌症疗法的反应，而癌症疗法可以驱动癌症的进化，而A3A/A3B相关的突变可能与癌症的预后和预后不良和治疗性有关。我们已经确定了A3G催化结构域和2'-脱氧 - Zebularine DNA的共结晶结构，并揭示了脱氨酸的过渡态。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'-脱氧 - Zebularine纳入了A3A/A3B的靶标序列中，并产生了有希望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。