Crepin Aurelie, Caffarri Stefano
Aix Marseille Universite, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Laboratoire de Genetique et Biophysique des Plantes, 13009 Marseille, France.
Curr Protein Pept Sci. 2018;19(7):699-713. doi: 10.2174/1389203719666180222101534.
Oxygenic photosynthesis provides energy and oxygen for almost all forms of life on earth. This process is based on the energy of photons, which is used to split water and use its electrons to reduce carbon atoms to create organic molecules and thus fix the light energy into a chemical form. Two photosytems working in series are involved in light harvesting and conversion. Both are multi-protein supercomplexes composed of a core complex, where the photochemical reaction takes place, and an antenna system involved in light harvesting. In plants and green algae, the antenna of photosystem II, the photosynthetic complex involved in water splitting, comprises the Light Harvesting Complex II (LHCII) trimers, the most abundant membrane protein on earth. LHCII is composed of highly conserved Lhcb isoforms and all green organisms count a high number of Lhcb. In vascular plants they are classified in three distinct subclasses, Lhcb1, 2 and 3, while in algae and non-vascular plants, these isoforms are less differentiated and called Lhcbm proteins. In this review, we compare LHCII proteins of different organisms, from green algae to angiosperms, and discuss the role of the modifications that occurred through evolution. We highlight the various functions of the different isoforms in photosynthesis, ranging from light harvesting, a common role to all these proteins, to regulations of photosynthesis that rely on specific isoforms.
氧光合作用为地球上几乎所有生命形式提供能量和氧气。这一过程基于光子的能量，光子能量用于分解水，并利用其电子还原碳原子以形成有机分子，从而将光能固定为化学形式。串联工作的两个光系统参与光的捕获和转换。两者都是多蛋白超复合体，由发生光化学反应的核心复合体和参与光捕获的天线系统组成。在植物和绿藻中，参与水分解的光合复合体光系统II的天线由捕光复合体II（LHCII）三聚体组成，LHCII三聚体是地球上最丰富的膜蛋白。LHCII由高度保守的Lhcb亚型组成，所有绿色生物都有大量的Lhcb。在维管植物中，它们被分为三个不同的亚类，Lhcb1、2和3，而在藻类和非维管植物中，这些亚型的差异较小，被称为Lhcbm蛋白。在这篇综述中，我们比较了从绿藻到被子植物等不同生物体的LHCII蛋白，并讨论了进化过程中发生的修饰的作用。我们强调了不同亚型在光合作用中的各种功能，从所有这些蛋白共有的捕光功能到依赖特定亚型的光合作用调节功能。
