為了避免光損傷、光合生物能夠熱耗散過(guò)量的吸收過(guò)程中的能量 稱為非光化學(xué)猝滅（NPQ）。雖然水已經(jīng)被廣泛的研究，主要參與者和淬火的機(jī)制 仍然爭(zhēng)論不休。這是由于在提取分子信息從體內(nèi)實(shí)驗(yàn) 和缺乏驗(yàn)證系統(tǒng)在體外實(shí)驗(yàn)中的困難。在這里，我們已經(jīng)創(chuàng)建了一個(gè)最小的細(xì)胞綠藻萊茵衣藻這是能夠接受的水。我們表明，LHCII，主要捕光復(fù)合物的藻類，其淬火 構(gòu)象反應(yīng)對(duì)pH值的變化不能切換。相反，少量的蛋白質(zhì)lhcsr1（捕光復(fù)合 應(yīng)激相關(guān)1）能夠產(chǎn)生一個(gè)大的，快速的，可逆的pH在LHCII含膜依賴淬火。 這些結(jié)果有力地表明，lhcsr1作為pH傳感器和它的壽命大 陣列調(diào)制激發(fā)態(tài)LHCII，也在觀察lhcsr3少NPQ解釋。討論可能的猝滅機(jī)理。
原文：
To avoid photodamage, photosynthetic organisms are able to thermally dissipate the energy absorbed in excess in a process known as nonphotochemical quenching (NPQ). Although NPQ has been studied extensively, the major players and the mechanism of quenching remain debated. This is a result of the difficulty in extracting molecular information from in vivo experiments and the absence of a validation system for in vitro experiments. Here, we have created a minimal cell of the green alga Chlamydomonas reinhardtiithat is able to undergo NPQ. We show that LHCII, the main light harvesting complex of algae, cannot switch to a quenched conformation in response to pH changes by itself. Instead, a small amount of the protein LHCSR1 (light-harvesting complex stress related 1) is able to induce a large, fast, and reversible pH-dependent quenching in an LHCII-containing membrane. These results strongly suggest that LHCSR1 acts as pH sensor and that it modulates the excited state lifetimes of a large array of LHCII, also explaining the NPQ observed in the LHCSR3-less mutant. The possible quenching mechanisms are discussed.
本文由專注于提供生物科技服務(wù)的齊一生物收集整理
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