The Carbon Dioxide Concentrating Mechanism of Chlamydomonas reinhardtii

Moroney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，允许这些生物体在非常低的外部二氧化碳浓度下光合自养生长。 这种二氧化碳浓缩机制是可诱导的;它只存在于在二氧化碳限制条件下生长的细胞中。 Moroney博士已经表明，具有二氧化碳浓缩机制的细胞具有存在于叶绿体被膜中的低二氧化碳诱导多肽LIP-36。 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特异性诱导的。 其中两个基因，1113和215，编码推定的跨膜蛋白。 最近，他获得了编码LIP-36的基因，并鉴定了编码内部碳酸酐酶的基因。 在这个奖项中，莫罗尼博士将研究C。reinhardtii通过使用三种方法。 在第一种方法中，他将继续描述一些已鉴定的基因和蛋白质。 第二种方法将是利用叶绿体被膜囊泡测量无机碳的运输。麦卡蒂，约翰霍普金斯大学。 第三种方法是利用细胞分级分离和免疫定位技术，将Rubisco和新发现的碳酸酐酶定位于叶绿体内。莱因哈德氏菌 该运输系统的蛋白质的表征将增加我们对藻类中的低二氧化碳调节以及叶绿体在这种光合适应中的作用的理解。 藻类的光合作用是地球能量循环的主要部分。 对其内在机制的研究将有助于我们对全球变化的理解。

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.