THE MITOCHONDRION OF AIDS-ASSOCIATED CRYPTOSPORIDIUM

艾滋病相关隐孢子虫的线粒体

• 批准号: 7357289
• 负责人: JANET S KEITHLY
• 金额: $ 2.54万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7357289
• 关键词: MITOCHONDRION; AIDS; ASSOCIATED; CRYPTOSPORIDIUM

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of our new NIH project is to elucidate the structure and function of the mitochondrion (mit) of AIDS-associated Cryptosporidium parvum. Our data indicate that C. parvum possesses an acristate, ribosome-studded mit and crystalloid body (CB) posterior to the nucleus that has cardiolipin and oligomycin- and cyanide-sensitive membrane potentials (??). The nucleus of C. parvum also encodes mit-specific adenylate kinase 2, cpn60, valyl t-RNA synthase, and the iron sulfur cluster (Isc) genes IscS, IscU, and ferredoxin (Fdx), whose iron sulfur proteins are asembled and mature within eukaryotic mit. One of these, IscS has a typical mit signal peptide that has been used to target GFP to yeast mitochondria. C. parvum also contains a biochemical relic that appears to link pyruvate metabolism in mit-bearing protists with amitochondriate protists. Most aerobic protists oxidatively decarboxylate pyruvate within a mit using pyruvate dehydrogenase, whereas most anaerobic protists use pyruvate ferredoxin oxidoreductase (PFO). Euglena gracilis is exceptional using instead a pyruvate:NADP+ oxidoreductase (PNO) which is fused to a NADPH:cytochrome P-450 reductase (CPR) within its facultatively anaerobic mit. Interestingly, C. parvum also encodes and expresses this PNO:CPR fused protein, although its subcellular location is as yet unknown. We plan to test the hypothesis that C. parvum has a functional, and structurally relic mit that differs substantially from that of most eukaryotes, including humans, which may serve as a new drug target. The RVBC is needed to resolve the structural relationships between the relic mit, nuclear membranes, and CB immediately adjacent to the mit. Through traditional TEM, we have been able to make some assumptions about the structure and interrelationship of these organelles, but a more detailed image analysis is essential if we want to show definitively whether the mit and crystalloid body are both involved in energy metabolism of this parasite. Specifically, we would like to determine the nature of the membranous whorls in the relic mit, the apparent flattened cristae in the CB, and most specifically to determine if these two organelles are both part of an unusual mit. Furthermore, it already appears that the ribosomes surrounding the organelle also surround the nuclear membrane. We need to understand the juxtaposition of the ER and NM both in situ and in isolated organelles. In some respects, the CB of C. parvum resembles the unusual paracrystalline organization with cubic symmetry of the mit from Chaos carolinensis, and for that reason we think it might also perform mit functions. The sizes of these organelles suggests that a combination of imaging techniques available in the RVBC would be extremely helpful in resolving the structural complexity of the Cp mit, CB, and surrounding membranes.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。我们新的NIH项目的目的是阐明与艾滋病相关的隐孢子虫的线粒体（MIT）的结构和功能。我们的数据表明，C. parvum具有敏捷的，核糖体的MIT和晶体体（CB），其后部具有心脂蛋白和寡霉素和氰化物敏感的膜电位（??）。 C. parvum的细胞核还编码MIT特异性腺苷酸激酶2，CPN60，Valyl T-RNA合酶和铁硫簇（ISC）基因ISCS，ISCU和铁氧蛋白（FDX），其铁硫蛋白在eukary sul sul sul硫蛋白（FDX）内是Eukary ouk yukaryotity in eukaryoto in eukaryotic mit。其中之一，ISC具有典型的MIT信号肽，该肽已用于将GFP靶向酵母线粒体。 C. parvum还包含一个生化遗物，该遗物似乎将含MIT的生物中的丙酮酸代谢与氨基化生物联系起来。大多数有氧生物使用丙酮酸脱氢酶在MIT中氧化脱羧酸丙酮酸丙酮酸丙酮酸，而大多数厌氧生物使用丙酮酸铁蛋白氧化还原酶（PFO）。 Euglena gracilis使用丙酮酸：NADP+氧化还原酶（PNO）是非凡的，它融合到了NADPH：在其疗法的MIT中融合到NADPH：细胞色素P-450还原酶（CPR）。有趣的是，C. parvum还编码并表达此PNO：CPR融合蛋白，尽管其亚细胞位置尚不清楚。我们计划检验以下假设：C。parvum具有一个功能性和结构性的MIT，该功能与大多数真核生物（包括人类）大多有所不同，包括人类，这可能是一种新的药物靶标。 需要RVBC来解决紧邻MIT的遗物MIT，核膜和CB之间的结构关系。通过传统的TEM，我们能够对这些细胞器的结构和相互关系做出一些假设，但是如果我们想确定地展示MIT和结晶体是否参与该寄生虫的能量代谢，则必须进行更详细的图像分析。具体而言，我们想确定遗物中心中膜螺纹的性质，CB中明显的扁平cristae，最具体地说是确定这两个细胞器是否都是不寻常的MIT的一部分。此外，似乎已经围绕细胞器的核糖体围绕着核膜。我们需要了解原位和孤立细胞器中ER和NM的并置。在某些方面，C. parvum的CB类似于与Carolinensis的MIT的立方对称性对称性的非同寻常的paracrystalline组织，因此，我们认为它也可能执行MIT功能。 这些细胞器的尺寸表明，RVBC中可用的成像技术的组合对于解决CP MIT，CB和周围膜的结构复杂性非常有帮助。