The role of the ZNG1 metallochaperone in the host response to infection

ZNG1 金属伴侣在宿主感染反应中的作用

• 批准号: 10753132
• 负责人: DAVID P. GIEDROC
• 金额: $ 56.3万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-05 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10753132
• 关键词: Ablation; Affect; Animals; Binding; Biochemical; Biological; Biology; Cell physiology; Cells; Chemicals; Client; Clinical; Communicable Diseases; Complex; Cytosol; Data; Defect; Developing Countries; Development; Dietary Intervention; Dietary Zinc; Enzymes; Etiology; Exhibits; Family; Gene Expression; Genetic Transcription; Growth; Guanosine Triphosphate Phosphohydrolases; Homeostasis; Host Defense; Human; Immune response; Incidence; Infection; Life; Ligands; Link; Maintenance; Malignant Neoplasms; Mediating; Metalloproteins; Metals; Micronutrients; Modeling; Molecular; Molecular Chaperones; Mus; N-terminal; Names; Nature; Nucleotides; Outcome; Peptide Hydrolases; Persons; Physiological; Physiology; Play; Population; Predisposition; Process; Proteins; Proteome; Public Health; Regulation; Reporting; Risk Factors; Role; Single Nucleotide Polymorphism; Starvation; Structure; Testing; Therapeutic; Tissues; Transition Elements; Translation Process; ZFHX3 gene; Zebrafish; Zinc; Zinc Fingers; Zinc deficiency; cellular development; cofactor; combat; defined contribution; experimental study; human disease; immune function; in vivo; infection risk; insight; metalloenzyme; methionyl aminopeptidase; mortality; nervous system disorder; nutrition; protein function; proteostasis; response; transcription factor

SUMMARY Zinc binding metalloproteins and metalloenzymes constitute approximately 10% of the vertebrate proteome and are essential for many cellular processes. Due to the critical importance of zinc to vertebrate physiology, zinc deficiency leads to growth defects, aberrant immune function, neurological disorders, cancers, and increased risk of infection. This is a pervasive public health problem considering that approximately half of the world's population suffers from dietary zinc deficiency, now the fifth most important risk factor for mortality in developing countries. Although the clinical link between Zn deficiency and infection is established, the molecular mechanisms are not well understood. Despite the known importance of zinc cofactors to cellular function, the mechanism by which zinc is inserted into metalloproteins is poorly understood. In this application we report our discovery of zinc-regulated GTPase metalloprotein activator 1 (Zng1) as the first reported zinc metallochaperone that inserts zinc into cognate client metalloproteins. We identify the protein processing enzyme methionine aminopeptidase 1 (Metap1) and the transcription factor zinc finger homeobox 3 (Zfhx3) as Zng1 clients, and we describe a conserved domain that mediates an interaction between Zng1 and these metalloproteins. This finding forms the basis of proposed structural, biochemical, and physiological experiments to define the mechanism of Zng1-dependent metal delivery to client proteins. Single nucleotide polymorphisms in Zng1 are associated with increased incidence of severe infections in humans, establishing an important link between Zng1 and infection in the zinc starved host. Zng1-dependent metal transfer increases the functional activities of Metap1 and Zfhx3, and loss of Zng1 activity in mice and zebrafish negatively impacts organismal development and increases susceptibility to multiple infectious diseases. Based on these findings, we propose a model whereby the Zng1 family of enzymes are evolutionarily conserved metallochaperones that transfer zinc to Metap1 and Zfhx3 during conditions of extreme zinc deficiency. We predict that this process of co-factor delivery leads to regulated protein processing through Metap1 and coordinated gene expression changes through Zfhx3. Combined, these activities help orchestrate the cellular response to infection during zinc starvation. Experiments described in this proposal will test this model and determine the molecular mechanism by which Zng1 transfers metal to Metap1 and Zfhx3, define the role of Zng1-client interactions in proteostasis and transcription, and reveal the in vivo contribution of Zng1 metal delivery to vertebrate defense against infection. Collectively, findings from this proposal will uncover the biological and pathophysiological relevance of this newly identified family of zinc metallochaperones and make important contributions to nutrition and infection biology.

概括 锌结合金属蛋白和金属酶约占脊椎动物蛋白质组的 10% 对于许多细胞过程至关重要。由于锌对脊椎动物生理至关重要，因此 缺乏会导致生长缺陷、免疫功能异常、神经系统疾病、癌症和增加 感染的风险。考虑到世界上大约一半的人，这是一个普遍的公共卫生问题 人口患有膳食锌缺乏症，目前已成为发展中国家第五大死亡风险因素 国家。尽管锌缺乏和感染之间的临床联系已被确立，但分子水平 机制尚未得到很好的理解。尽管已知锌辅助因子对细胞功能的重要性， 锌插入金属蛋白的机制尚不清楚。在此应用程序中，我们报告了我们的 发现锌调节的 GTP 酶金属蛋白激活剂 1 (Zng1)，这是第一个报道的锌金属伴侣 将锌插入同源客户金属蛋白中。我们确定了蛋白质加工酶蛋氨酸 氨肽酶 1 (Metap1) 和转录因子锌指同源盒 3 (Zfhx3) 作为 Zng1 客户，我们 描述了介导 Zng1 和这些金属蛋白之间相互作用的保守结构域。这一发现 构成了所提出的结构、生化和生理学实验的基础，以定义其机制 Zng1 依赖性金属向客户蛋白的传递。 Zng1 中的单核苷酸多态性与 人类严重感染的发生率增加，建立了 Zng1 与感染之间的重要联系 在缺锌的宿主中。 Zng1 依赖性金属转移增加 Metap1 和 Zfhx3 的功能活性， 小鼠和斑马鱼中 Zng1 活性的丧失会对生物体发育产生负面影响并增加 对多种传染病的易感性。基于这些发现，我们提出了一个模型，其中 Zng1 酶家族是进化上保守的金属伴侣，可在 极度缺锌的情况。我们预测这种辅因子传递过程会产生受调节的蛋白质 通过 Metap1 进行处理并通过 Zfhx3 协调基因表达变化。这些活动结合起来 帮助协调细胞在缺锌期间对感染的反应。本提案中描述的实验 将测试该模型并确定 Zng1 将金属转移到 Metap1 和 Zfhx3 的分子机制， 定义了 Zng1-client 相互作用在蛋白质稳态和转录中的作用，并揭示了 Zng1-client 相互作用的体内贡献 Zng1 金属递送至脊椎动物防御感染。总的来说，该提案的调查结果将揭示 这个新发现的锌金属伴侣家族的生物学和病理生理学相关性以及 对营养和感染生物学做出重要贡献。