Carrigan Matthew A, Uryasev Oleg, Frye Carole B, Eckman Blair L, Myers Candace R, Hurley Thomas D, Benner Steven A
Department of Natural Sciences, Santa Fe College, Gainesville, FL 32606; Foundation for Applied Molecular Evolution, Gainesville, FL 32604; and
Foundation for Applied Molecular Evolution, Gainesville, FL 32604; and.
Proc Natl Acad Sci U S A. 2015 Jan 13;112(2):458-63. doi: 10.1073/pnas.1404167111. Epub 2014 Dec 1.
Paleogenetics is an emerging field that resurrects ancestral proteins from now-extinct organisms to test, in the laboratory, models of protein function based on natural history and Darwinian evolution. Here, we resurrect digestive alcohol dehydrogenases (ADH4) from our primate ancestors to explore the history of primate-ethanol interactions. The evolving catalytic properties of these resurrected enzymes show that our ape ancestors gained a digestive dehydrogenase enzyme capable of metabolizing ethanol near the time that they began using the forest floor, about 10 million y ago. The ADH4 enzyme in our more ancient and arboreal ancestors did not efficiently oxidize ethanol. This change suggests that exposure to dietary sources of ethanol increased in hominids during the early stages of our adaptation to a terrestrial lifestyle. Because fruit collected from the forest floor is expected to contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on trees, this transition may also be the first time our ancestors were exposed to (and adapted to) substantial amounts of dietary ethanol.
古遗传学是一个新兴领域，它能从现已灭绝的生物中复活祖先蛋白质，以便在实验室中检验基于自然历史和达尔文进化论的蛋白质功能模型。在此，我们复活了灵长类祖先的消化性乙醇脱氢酶（ADH4），以探索灵长类与乙醇相互作用的历史。这些复活酶不断演变的催化特性表明，我们的猿类祖先在大约1000万年前开始利用森林地面时，获得了一种能够代谢乙醇的消化脱氢酶。我们更古老的树栖祖先体内的ADH4酶不能有效地氧化乙醇。这一变化表明，在人类适应陆地生活方式的早期阶段，饮食中乙醇来源的暴露增加。由于从森林地面采集的水果预计比挂在树上的类似水果含有更高浓度的发酵酵母和乙醇，这种转变也可能是我们的祖先首次接触（并适应）大量饮食乙醇。
