The Carbon Dioxide Concentrating Mechanism of Chlamydomonas reinhardtii

莱茵衣藻的二氧化碳浓缩机制

• 批准号: 9632087
• 负责人: James Moroney
• 金额: $ 36.85万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9632087&HistoricalAwards=false
• 关键词: Carbon; Dioxide; Concentrating; Mechanism; Chlamydomonas

9632087 Moroney Unicellular algae, including Chlamydomonas reinhardtii, have the capacity to concentrate carbon dioxide internally, allowing these organisms to grow photoautotrophically at very low external carbon dioxide concentrations. This carbon dioxide concentrating mechanism is inducible; it is present only in cells that have been grown with limiting carbon dioxide conditions. Dr. Moroney has shown that cells with the carbon dioxide concentrating mechanism have the low carbon dioxide-inducible polypeptide, LIP-36, present in the chloroplast envelope. He also has identified six genes that are specifically induced by growth on low carbon dioxide. Two of these genes, 1113 ans 215, encode putative transmembrane proteins. Recently he has obtained the gene encoding LIP-36 and has identified a gene encoding an internal carbonic anhydrase. In this award, Dr. Moroney will study the carbon dioxide concentrating mechanism in C. reinhardtii by using three approaches. In the first approach he will continue to characterize some of the genes and proteins identified. The second approach will be to measure inorganic carbon transport using chloroplast envelope vesicles in collaboration with Dr. Richard E. McCarty, Johns Hopkins University. The third approach will be to use cellular fractionation and immunolocalization to localize rubisco and the newly discovered carbonic anhydrase within the chloroplast of C. reinhardtii. The characterization of the proteins of this transport system will increase our understanding of the low carbon dioxide adjustment in algae and the role of the chloroplast in this photosynthetic adaptation. Algal photosynthesis contributes a major portion of the earth's energy cycle. Studies of its underlying mechanisms will contribute to our understanding of global change.

9632087种莫罗尼单细胞藻类，包括莱茵衣藻，具有在内部浓缩二氧化碳的能力，使这些生物能够在外部二氧化碳浓度极低的情况下进行光自养生长。这种二氧化碳浓缩机制是可诱导的；它只存在于二氧化碳限制条件下培养的细胞中。莫罗尼博士已经证明，具有二氧化碳浓缩机制的细胞具有低二氧化碳诱导多肽LIP-36，存在于叶绿体被膜中。他还确定了六个基因，这些基因是由低二氧化碳环境下的生长诱导的。其中两个基因，1113和215，编码假定的跨膜蛋白。最近，他获得了编码LIP-36的基因，并鉴定了一个编码内部碳酸氢酶的基因。在这一奖项中，莫罗尼博士将通过三种方法研究莱茵梭菌的二氧化碳浓缩机制。在第一种方法中，他将继续描述一些已识别的基因和蛋白质。第二种方法将是与约翰·霍普金斯大学的理查德·E·麦卡蒂博士合作，使用叶绿体被膜小泡来测量无机碳的运输。第三种方法是使用细胞分离和免疫定位来定位Rubisco和新发现的莱茵哈迪叶绿体中的碳酸氢酶。对这一运输系统蛋白质的表征将增加我们对藻类低二氧化碳调节以及叶绿体在这种光合作用适应中的作用的理解。藻类光合作用贡献了地球能量循环的主要部分。对其潜在机制的研究将有助于我们对全球变化的理解。