The role of NAGK cysteine deprotonation in nutrient stress and cancer progression

NAGK 半胱氨酸去质子化在营养应激和癌症进展中的作用

• 批准号: 10652823
• 负责人: JOHN BLENIS
• 金额: $ 8.48万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-21 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10652823
• 关键词: Attention; Binding; Cell Communication; Cells; Cysteine; Data; Detection; Development; Disease Progression; Ensure; Environment; Environmental Risk Factor; Event; Frequencies; Global Change; Glutamine; Growth; Hexosamines; Immune Evasion; Iodoacetamide; Knock-out; Label; Malignant Neoplasms; Mediating; Metabolic; Modification; N-Acetylglucosamine kinase; Neoplasm Metastasis; Nucleotides; Nutrient; Nutrient Depletion; Oxidants; Pathway interactions; Perfusion; Phosphorylation; Phosphotransferases; Polysaccharides; Predisposition; Process; Property; Proteins; Proteome; Reaction; Recycling; Regulation; Research; Resources; Role; Signal Transduction; Site; Stimulus; Stress; Sulfhydryl Compounds; Therapeutic; Therapeutic Intervention; Tissues; Tumor Promotion; Work; biological adaptation to stress; cancer cell; cost; deprivation; deprotonation; extracellular; glycosylation; glycosyltransferase; neoplastic cell; novel; oxidation; programs; protonation; resilience; response; small molecule; sugar; sugar nucleotide; therapeutic target; tumor; tumor growth; tumor microenvironment; tumor progression; uptake

PROJECT SUMMARY/ ABSTRACT Changes in cellular glycosylation support cancer growth and progression, but the biosynthetic pathways that supply the required nucleotide-sugar precursors are resource intensive. The cell therefore utilizes salvage pathways to recycle free sugars following glycan degradation or extracellular uptake, offsetting the need for their de novo synthesis. Little is known about the extent to which cancer cells rely on sugar salvage pathways or how these pathways are regulated. Recently, the salvage kinase responsible for phosphorylating N- acetylglucosamine (GlcNAc) for reuse by the hexosamine biosynthetic pathway, N-acetyl-D-glucosamine kinase (NAGK), was found to support tumor growth, providing early evidence that cancer cells may indeed rely heavily on salvage. Preliminary data presented here show that NAGK is deprotonated at two cysteines in response to nutrient limitation, a condition frequently encountered in the tumor microenvironment. Cysteine deprotonation can alter protein activity and promote subsequent oxidation. This deprotonation is observed not just on NAGK, but on proteins throughout the cell in what may be a previously unrecognized adaptation to stress. Cysteines, especially in the deprotonated thiolate state, serves as ready sites of covalent inhibition by small molecule electrophiles. Thus, the wide-spread increase in thiolates in response to nutrient limitation may represent a class of proteins that are more responsive to covalent inhibition within stressed tumor cells than when in their protonated thiol state in healthy, perfused tissue. The aims detailed in this proposal will first characterize the effect of cysteine deprotonation on NAGK activity and its role in tumor growth and will then focus on identifying the global changes in cysteine protonation status in response to nutrient limitation as well as the environmental factors that promote this deprotonation. This work will characterize, both mechanistically and broadly, a novel stress response that may promote tumor progression despite nutrient limitation but that may also render the tumor more vulnerable to therapeutic intervention with small molecule electrophiles.

项目摘要/摘要 细胞糖基化的变化支持癌症的生长和进展，但生物合成途径是 提供所需的核苷酸 - 糖前体是资源密集的。因此，细胞利用打捞 聚糖降解或细胞外摄取后，回收无糖的途径，抵消了对其的需求 从头综合。关于癌细胞依赖糖挽救途径的程度或如何 这些途径受到调节。最近，负责磷酸化n-的打捞激酶 乙酰葡萄糖（GLCNAC）通过己糖胺生物合成途径，N-乙酰基-D-D-葡萄糖激酶再利用 （Nagk）发现支持肿瘤生长，提供了早期的证据，表明癌细胞确实可能严重依赖 打捞。此处介绍 营养限制，这种情况在肿瘤微环境中经常遇到。半胱氨酸去质子化 可以改变蛋白质活性并促进随后的氧化。这种去质子不仅在nagk上观察到 但是，在整个细胞中的蛋白质上可能是先前无法识别的压力适应。半胱氨酸， 尤其是在去质子化的硫醇酸盐状态下，作为小分子共价抑制作用的现成部位 电力。因此，响应营养限制的硫醇盐的广泛增加可能代表一个类别 与在压力肿瘤细胞内共价抑制更敏感的蛋白质相比 质子化的硫醇状态在健康的，灌注的组织中。该提案中详细介绍的目的将首先描述 半胱氨酸去质子化对NAGK活性及其在肿瘤生长中的作用的影响，然后专注于识别 响应营养限制以及环境的全球半胱氨酸质子化状态的全球变化 促进这种去质子化的因素。这项工作将在机械和广泛的小说上表征 尽管营养限制，但可能会促进肿瘤进展的压力反应，但这也可能导致 肿瘤更容易受到小分子电力的治疗干预。