KSHVmediated regulation of proline metabolism

KSHV介导的脯氨酸代谢调节

• 批准号: 10293612
• 负责人: Jae U Jung
• 金额: $ 47.91万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-23 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10293612
• 关键词: 3-Dimensional; Affect; Amino Acids; Anabolism; Binding; C-terminal; Cell membrane; Complex; Enzyme Activation; Enzymes; Etiology; Gene Library; Genes; Glutamine; Glycoproteins; Growth; Herpesviridae; Human Herpesvirus 8; ITAM; Impairment; Innate Immune Response; Kaposi Sarcoma; Ligase; Lymphoma; Malignant Neoplasms; Mediating; Metabolic; Metabolic Pathway; Metabolism; Mitochondria; Molecular; Multienzyme Complexes; N-terminal; Neoplasm Metastasis; Nucleic Acids; Nutrient; Oncogenic; Oncoproteins; Oral; Ornithine-oxo-acid aminotransferase; Pathogenesis; Pathway interactions; Peptides; Pleural effusion disorder; Production; Proliferating; Proline; Protein Isoforms; Proteome; Proto-Oncogenes; Regulation; Research; Role; Signal Transduction; Substrate Interaction; TP53 gene; Testing; Variant; Viral; Virus; base; cancer cell; cancer therapy; cell growth; deamidation; enzyme biosynthesis; gene product; inhibitor/antagonist; lytic replication; mimetics; monolayer; mouse model; neoplastic cell; novel; overexpression; pyrroline 5 carboxylate reductase; screening; sensor; small molecule; three dimensional cell culture; tumor; tumor metabolism; two-dimensional; viral RNA

Project Summary/Abstract Metabolic reprograming has been readily recognized as part of the hallmarks of cancer. Particularly, proline metabolism is critically important for tumor metastasis, as pyrroline-5-carboxylate reductase (P5CR), a key mitochondrial proline biosynthesis enzyme, is highly overexpressed in various metastasized tumors and to promote tumor cell growth. This suggests that the proline synthesis pathway is an attractive target for cancer treatment. Kaposi’s sarcoma-associated herpesvirus (KSHV) is one of oral herpesviruses and causes Kaposi’s sarcoma and pleural effusion lymphoma. The proposed research is directed toward investigating the molecular mechanism of KSHV-mediated regulation of proline metabolism. We have shown that KSHV K1 glycoprotein elicits intracellular signal transduction for growth transformation in a C-terminal immunoreceptor tyrosine-based activation motif (ITAM)-dependent manner. Surprisingly, we discovered (Aim 1) that the unphosphorylated K1 directly interacted with mitochondrial P5CR in an ITAM-independent manner and this interaction activated its enzymatic activity, increasing intracellular proline synthesis. Furthermore, KSHV gene screening identified that ORF75, an enzyme-deficient viral glutamine amidotransferase (vGAT), functions as a substrate recruiter by binding one of host GATs, PFAS (phosphoribosylformylglycinamidine synthetase), and vGAT/PFAS enzyme complex deamidates intracellular nucleic acid sensors, evading host innate immune response. Furthermore, our proteome-wide deamidation screen discovered (Aim 2) that the vGAT/PFAS complex effectively induced the deamidation of P5C synthase (P5CS) during KSHV lytic replication. Based on these, we hypothesize a novel viral regulation of proline metabolism where KSHV utilizes two gene products to deregulate proline synthesis pathway: K1 activates the enzymatic activity of P5CR in an ITAM- independent manner and vGAT collaborates with host PFAS to induce the deamidation of P5CS, which ultimately synergizes to enhance proline synthesis and cell growth transformation (Aim 3). The proposed studies will provide an understanding of a novel oncogenic strategy of KSHV to induce proline metabolism for virus-induced pathogenesis.

项目摘要/摘要 代谢重编程很容易被认为是癌症标志的一部分。特别， 脯氨酸代谢对肿瘤转移至关重要，因为吡咯酸5-羧酸盐还原酶 （P5CR）是一种关键的线粒体脯氨酸生物合成酶，在各种 转移肿瘤并促进肿瘤细胞生长。这表明脯氨酸合成 途径是癌症治疗的有吸引力的靶标。卡波西与肉瘤相关的疱疹病毒 （KSHV）是口服疱疹病毒之一，会导致Kaposi的肉瘤和胸膜出口淋巴瘤。 拟议的研究旨在研究KSHV介导的分子机制 调节脯氨酸代谢。我们已经表明，KSHV K1糖蛋白会引起细胞内 基于C末端免疫受体酪氨酸中生长转化的信号转移 激活基序（ITAM）依赖性方式。令人惊讶的是，我们发现（目标1） 未磷酸化的K1直接与线粒体P5CR相互作用以ITAM独立的方式相互作用 这种相互作用激活了其酶促活性，增加了细胞内脯氨酸的合成。 此外，KSHV基因筛选确定ORF75是一种缺乏酶的病毒谷氨酰胺 通过结合宿主GAT，PFAS之一，胺基转移酶（VGAT）作为底物招募者起作用 （磷酸贝糖基甘氨酸合成酶）和VGAT/PFAS酶复合物脱膜 细胞内核酸传感器，逃避宿主先天免疫反应。此外，我们的 发现（AIM 2）VGAT/PFAS复合物有效地发现了蛋白质组的死亡筛查（AIM 2） 在KSHV裂解复制期间诱导P5C合酶（P5C）的死亡。基于这些，我们 假设对脯氨酸代谢的新型病毒调节，其中KSHV利用了两个基因产物 放大管制脯氨酸的合成途径：K1激活了ITAM-的P5CR的酶促活性 独立的方式和VGAT与主机PFA合作，诱导P5C的死亡， 最终合成以增强脯氨酸的合成和细胞生长转化（AIM 3）。 拟议的研究将提供对KSHV新型致癌策略的理解 脯氨酸代谢用于病毒诱导的发病机理。