Canadian Institute for Advanced Research, Botany Department, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
Nat Commun. 2011 Feb 8;2:183. doi: 10.1038/ncomms1188.
Proteorhodopsins are light-driven proton pumps involved in widespread phototrophy. Discovered in marine proteobacteria just 10 years ago, proteorhodopsins are now known to have been spread by lateral gene transfer across diverse prokaryotes, but are curiously absent from eukaryotes. In this study, we show that proteorhodopsins have been acquired by horizontal gene transfer from bacteria at least twice independently in dinoflagellate protists. We find that in the marine predator Oxyrrhis marina, proteorhodopsin is indeed the most abundantly expressed nuclear gene and its product localizes to discrete cytoplasmic structures suggestive of the endomembrane system. To date, photosystems I and II have been the only known mechanism for transducing solar energy in eukaryotes; however, it now appears that some abundant zooplankton use this alternative pathway to harness light to power biological functions.
紫膜质体光驱动质子泵广泛参与光合作用。10 年前在海洋变形菌中首次发现紫膜质体，现在已知它通过水平基因转移在不同的原核生物中传播，但在真核生物中却很奇怪地不存在。在这项研究中，我们表明，紫膜质体已经通过水平基因转移从细菌中获得，至少在两次独立的甲藻原生动物中发生。我们发现，在海洋捕食者 Oxyrrhis marina 中，紫膜质体确实是表达最丰富的核基因，其产物定位于离散的细胞质结构，提示其与内膜系统有关。迄今为止，光系统 I 和 II 一直是真核生物中已知的唯一将太阳能转化为生物功能的机制；然而，现在似乎一些丰富的浮游动物利用这种替代途径利用光来驱动生物功能。
