Dulermo Rémi, Gamboa-Meléndez Heber, Michely Stéphanie, Thevenieau France, Neuvéglise Cécile, Nicaud Jean-Marc
UMR1319 Micalis, INRA, Jouy-en-Josas, F-78352, France.
Microbiologyopen. 2015 Feb;4(1):100-20. doi: 10.1002/mbo3.225. Epub 2014 Dec 16.
Jen proteins in yeast are involved in the uptake of mono/dicarboxylic acids. The Jen1 subfamily transports lactate and pyruvate, while the Jen2 subfamily transports fumarate, malate, and succinate. Yarrowia lipolytica has six JEN genes: YALI0B19470g, YALI0C15488g, YALI0C21406g, YALI0D20108g, YALI0D24607g, and YALI0E32901g. Through phylogenetic analyses, we found that these genes represent a new subfamily, Jen3 and that these three Jen subfamilies derivate from three putative ancestral genes. Reverse transcription-PCR. revealed that only four YLJEN genes are expressed and they are upregulated in the presence of lactate, pyruvate, fumarate, malate, and/or succinate, suggesting that they are able to transport these substrates. Analysis of deletion mutant strains revealed that Jen3 subfamily proteins transport fumarate, malate, and succinate. We found evidence that YALI0C15488 encodes the main transporter because its deletion was sufficient to strongly reduce or suppress growth in media containing fumarate, malate, or succinate. It appears that the other YLJEN genes play a minor role, with the exception of YALI0E32901g, which is important for malate uptake. However, the overexpression of each YLJEN gene in the sextuple-deletion mutant strain ΔYLjen1-6 revealed that all six genes are functional and have evolved to transport different substrates with varying degrees of efficacy. In addition, we found that YALI0E32901p transported succinate more efficiently in the presence of lactate or fumarate.
酵母中的Jen蛋白参与单羧酸/二羧酸的摄取。Jen1亚家族转运乳酸和丙酮酸，而Jen2亚家族转运富马酸、苹果酸和琥珀酸。解脂耶氏酵母有六个JEN基因：YALI0B19470g、YALI0C15488g、YALI0C21406g、YALI0D20108g、YALI0D24607g和YALI0E32901g。通过系统发育分析，我们发现这些基因代表一个新的亚家族Jen3，并且这三个Jen亚家族源自三个假定的祖先基因。逆转录PCR显示只有四个YLJEN基因表达，并且它们在乳酸、丙酮酸、富马酸、苹果酸和/或琥珀酸存在时上调，表明它们能够转运这些底物。缺失突变体菌株分析显示Jen3亚家族蛋白转运富马酸、苹果酸和琥珀酸。我们发现证据表明YALI0C15488编码主要转运蛋白，因为其缺失足以强烈降低或抑制在含有富马酸、苹果酸或琥珀酸的培养基中的生长。似乎其他YLJEN基因起次要作用，除了YALI0E32901g，它对苹果酸摄取很重要。然而，在六重缺失突变体菌株ΔYLjen1-6中每个YLJEN基因的过表达表明所有六个基因都有功能，并且已经进化为以不同程度的效率转运不同的底物。此外，我们发现YALI0E32901p在乳酸或富马酸存在时更有效地转运琥珀酸。
