Heme Protein Sensors in Prokaryotes

原核生物中的血红素蛋白传感器

• 批准号: 7048315
• 负责人: MICHAEL A. MARLETTA
• 金额: $ 28.32万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-22 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7048315
• 关键词: Escherichia coli; Raman spectrometry; bacterial proteins; biological signal transduction; crystallization; enzyme activity; gene expression; hemoprotein; histidine; ligands; molecular cloning; nitric oxide; oxygen; point mutation; prokaryote; protein binding; protein kinase; protein protein interaction; protein purification; protein structure function; transfection

DESCRIPTION (provided by applicant): A molecular level understanding of how key signaling proteins distinguish between nitric oxide (NO) and oxygen is the central focus of this proposal. NO is a key signaling molecule that plays a central role in blood vessel dilation, penile erections and other smooth muscle related responses. NO also is a signaling agent in the central nervous system and is used by the immune system to kill infectious organisms and tumor cells. NO is toxic and chemically reactive and major questions remain concerning how this molecule is used with specificty in humans and other animals. Recent observations clearly show that bacteria contain a family of proteins that are closely related to the enzyme guanylate cyclase, the NO receptor (sensor) in humans. However, while in some cases our hypothesis is that these prokaryotic proteins are involved in NO sensing, in others is appears that they are O2 sensors. How are these proteins able to distinguish NO from oxygen is the broad overall goal of this proposal as well as understanding function. The results obtained are likely to explain not only how NO and oxygen are sensed in bacteria but will also shed light on how these molecules are sensed and used in humans and other animals. Further, the work will provide novel data on why some bacterial pathogens are not killed by NO. Experimentally this project will involve general tools of molecular biology and protein characterization plus advanced spectroscopic techniques such as resonance Raman spectroscopy. In addition, protein crystallization structure determination and functional studies by gene transfection into E. coli will be used. The structural determinants that allow for this difficult discrimination are not obvious and remain at the heart of biological recognition and specificity of signaling. What appeared for the last 10 years to be a characterization of proteins that bind NO has now been expanded to include oxygen. CO signaling is an active area of research lacking among other things a specific receptor. Proteins in this family are likely possibilities for this key, missing component. Furthermore, when pathogens respond to a NO challenge from the immune system, they could use a receptor system similar to the apparent NO signaling system hypothesized to be contained in a number of facultative aerobic bacteria.

描述（由申请人提供）：对关键信号蛋白如何区分一氧化氮（NO）和氧气的分子水平是该建议的主要重点。 NO是一个关键的信号分子，在血管扩张，阴茎勃起和其他平滑肌相关的反应中起着核心作用。 NO也是中枢神经系统中的信号传导剂，免疫系统使用来杀死传染性生物和肿瘤细胞。 NO是有毒和化学反应性的，并且关于该分子如何与人类和其他动物的特定分子一起使用仍然存在的主要问题。最近的观察结果清楚地表明，细菌含有与人类中的NO受体（传感器）密切相关的蛋白质。但是，尽管在某些情况下，我们的假设是这些核蛋白不参与任何传感，但在其他情况下似乎是O2传感器。这些蛋白质如何能够将NO与氧气区分开来是该提案的广泛总体目标以及理解功能。获得的结果不仅可以解释细菌中NO和氧气的感觉如何，还可以阐明这些分子如何在人类和其他动物中感测和使用。此外，这项工作将提供有关为什么某些细菌病原体不会被否杀死的新数据。在实验上，该项目将涉及分子生物学和蛋白质表征以及晚期光谱技术（例如共振拉曼光谱）的一般工具。另外，将使用蛋白质结晶结构测定和通过基因转染向大肠杆菌的功能研究。允许这种困难歧视的结构决定因素并不明显，并且是信号传导的生物学识别和特异性的核心。在过去的10年中，似乎是结合NO的蛋白质的表征，现已扩展到包括氧气。 CO信号传导是缺乏特定受体的研究的活跃领域。该家族中的蛋白质可能是该密钥缺失的可能性。此外，当病原体应对免疫系统的无挑战时，他们可以使用类似于明显没有信号系统的受体系统，假设在许多辅助有氧细菌中包含的信号传导系统。