Can engineering protein subcellular localization protect yeast cells from toxic fermentation inhibitors?

生物经济是加拿大增长最快的行业之一。生物产品，包括生物燃料、生物化学和生物材料，是由农业、林业、水产养殖甚至垃圾等生物质产生的可再生产品。这主要是通过利用微生物发酵将生物质转化为生物产品来实现的，类似于酵母将葡萄转化为葡萄酒。加拿大统计局2015年生物制品生产和开发调查显示，190家加拿大公司生产生物制品，估计销售额为43亿美元，高于2009年的13亿美元。尽管生物经济增长迅速，但重大挑战依然存在。新兴产业已经转向在农业和林业废弃物中发现的木质纤维素生物质，以及在边缘土地上种植的草等能源作物。木质纤维素的生物转化是一个两步过程，包括将生物质水解或分解成混合糖，然后由酵母等微生物发酵转化为生物产品。然而，除了释放糖外，水解步骤还会产生复杂的有毒化合物混合物，严重抑制酵母的生长和发酵。以酵母为基础的生物制品工业面临的最大挑战之一是开发能够在木质纤维素水解物中发现的有毒化学物质混合物中存活的酵母。简单地说，如果它们死了，酵母就不能发酵。我的研究项目利用各种尖端的全基因组或“组学”技术来发现单个和复杂的水解毒素混合物杀死酵母的机制。最近我们有了一个令人惊讶的发现，一些蛋白质在接触毒素后会改变细胞内的位置，这种蛋白质位置的改变可能有助于保护细胞免受毒素的侵害。我们的工作让我们想知道，我们是否可以利用蛋白质定位来增加对水解毒素的抵抗力，并最终提高生物产品的产量。这项研究计划的目标是确定在毒素暴露后改变细胞内位置的蛋白质，确定它们如何以及为什么改变位置，包括位置的变化是否提供了对毒素的保护。我们的研究将首次评估工程蛋白亚细胞定位在大规模提高毒素耐受性方面的潜力，并可能导致工业酵母开发的突破性进展。这笔拨款还将解决生物制品行业的另一个主要障碍，即训练有素的人员的可用性。目前，该行业有超过1000人从事研发或技术人员工作，但17.1%的公司在2015年报告了由于无法找到HQP而空缺的职位。该研究项目将为加拿大这一领域的持续发展提供最先进的HQP知识。

The Bioeconomy is one of Canada's fast growing sectors. Bioproducts, including biofuels, biochemical and biomaterials, are renewable products generated from biomass such as agricultural, forestry, aquaculture and even garbage. This is largely done through conversion of biomass into bioproducts using microorganism-based fermentation, similar to yeast converting grapes to wine. Statistics Canada's 2015 Bioproducts Production and Development Survey indicate that 190 Canadian companies were manufacturing bioproducts with an estimated sales of $4.3 billion, up from $1.3 Billion in in 2009. Despite a fast growing Bioeconomy, major challenges remain. The emerging industry has turned towards lignocellulosic biomass found in agricultural and forestry waste, as well as energy crops such as grasses grown on marginal lands. The bioconversion of lignocellulose is a two-step process involving the hydrolysis or breaking down of the biomass into mixed sugars that are then converted to bioproducts by fermentation by microorganisms like yeast. However, in addition to the release of sugars, the hydrolysis step also generates a complex mix of toxic compounds that severely inhibit yeast growth and fermentation. One of the greatest challenges for yeast-based bioproduct industry is the development of yeast that can survive in the toxic mix of chemicals found in lignocellulosic hydrolysates. Simple put, yeast cannot ferment if they are dead. My research program exploits a variety of cutting-edge genome-wide or "OMICs" technologies to discover the mechanisms by which both individual and complex mixtures of hydrolysate toxins kill yeast. Recently we made the surprising discovery that some proteins change location within the cell upon exposure to a toxin and that this change of protein location may help protect the cell from the toxins. Our work has lead us to ask if we can exploit protein localization to increase resistance to hydrolysate toxins and ultimately improve bioproduct production. The goal of this research program is to identify proteins that change location within the cell upon toxin exposure, identify how and why they change location, including if the change in location offers protection from toxins. Our study will be the first to assess the potential of engineering protein subcellular localization to improve toxin tolerance on a large scale and may lead to groundbreaking advances in the development of industrial yeast. This grant will also address another major hurdle of the Bioproduct Industry, the availability of highly trained personal. Presently over 1000 people are employed in R&D or technicians with in this industry, but 17.1% of companies reported vacant positions due to an inability to find HQP in 2015. This research program will produce HQP with knowledge of state-of-the-art technologies needed for the continued growth of this sector in Canada.