Faculty of Biology, Technion, Haifa 32000, Israel.
Grand Technion Energy Program, Technion, Haifa 32000, Israel.
Int J Mol Sci. 2023 Jan 28;24(3):2503. doi: 10.3390/ijms24032503.
The emergence of chlorophyll-containing light-harvesting complexes (LHCs) was a crucial milestone in the evolution of photosynthetic eukaryotic organisms. Light-harvesting chlorophyll-binding proteins form complexes in proximity to the reaction centres of photosystems I and II and serve as an antenna, funnelling the harvested light energy towards the reaction centres, facilitating photochemical quenching, thereby optimizing photosynthesis. It is now generally accepted that the LHC proteins evolved from LHC-like proteins, a diverse family of proteins containing up to four transmembrane helices. Interestingly, LHC-like proteins do not participate in light harvesting to elevate photosynthesis activity under low light. Instead, they protect the photosystems by dissipating excess energy and taking part in non-photochemical quenching processes. Although there is evidence that LHC-like proteins are crucial factors of photoprotection, the roles of only a few of them, mainly the stress-related psbS and lhcSR, are well described. Here, we summarize the knowledge gained regarding the evolution and function of the various LHC-like proteins, with emphasis on those strongly related to photoprotection. We further suggest LHC-like proteins as candidates for improving photosynthesis in significant food crops and discuss future directions in their research.
叶绿素含量光捕获复合物（LHCs）的出现是光合真核生物进化过程中的一个关键里程碑。光捕获叶绿素结合蛋白在靠近光系统 I 和 II 的反应中心形成复合物，并作为天线，将捕获的光能引导至反应中心，促进光化学猝灭，从而优化光合作用。现在人们普遍认为，LHC 蛋白是从 LHC 样蛋白进化而来的，LHC 样蛋白是一类含有多达四个跨膜螺旋的多样化蛋白家族。有趣的是，LHC 样蛋白在低光照下不会参与光捕获来提高光合作用活性。相反，它们通过耗散多余的能量和参与非光化学猝灭过程来保护光系统。尽管有证据表明 LHC 样蛋白是光保护的关键因素，但只有少数几种蛋白的作用得到了很好的描述，主要是与应激相关的 psbS 和 lhcSR。在这里，我们总结了关于各种 LHC 样蛋白的进化和功能的知识，重点介绍了与光保护密切相关的 LHC 样蛋白。我们进一步提出 LHC 样蛋白是提高重要粮食作物光合作用的候选蛋白，并讨论了它们的研究方向。
