高渗胁迫对光滑球拟酵母蛋白质组的影响

The proteome of the Torulopsis glabrata under hyperosmotic stress

光滑球拟酵母(Torulopsis glabrata)在生产丙酮酸的过程中,发酵液渗透压不断提高,导致细胞生长缓慢,影响丙酮酸的持续积累。实验通过二维电泳和同位素标记相对和绝对定量(iTRAQ)技术,比较不同渗透压条件下蛋白质组的差异。结果表明,在渗透压为1 765、2 603和3 324 mOsmol/kg时,相对于对照条件(860mOsmol/kg),分别有125、91和109个蛋白表达水平上调,94、89和78个蛋白表达水平下调,其中中心代谢和能量代谢途径的蛋白质表达量明显提高。此外,研究还发现,渗透压胁迫可诱导超氧化物歧化酶和富脯蛋白的表达量增加,前者可能和高渗环境下活性氧簇的积累有关,而后者可能与胞内脯氨酸的积累有关。该文为后续研究如何提高T.glabrata抵御高渗胁迫的能力提供理论依据。

During the pyruvate production by Torulopsis glabrata, the osmotic stress in culture broth gradually in- creased. As a result, cell growth and acid production slowed. The proteome of the T. glabrata under hyperosmotic stress was investigated by two-dimensional polyacrylamide gel electrophoresis （2D-PAGE） and isobaric tag for relative and absolute quantitation （iTRAQ）. Compared to normal condition （860 mOsmol/kg）, 125, 91, 109 proteins were upregulated and 94, 89, 78 proteins were downregulated under osmolarity of 1765 mOsmol/kg, 2603 mOsmol/kg, and 3324 mOsmol/kg. The protein expression involved in central metabolic pathways and energy metabolism showed apparently upregulation. Furthermore, the expression levels of superoxide dismutase and verprolin increased under hy- perosmotic conditions, of which the former might due to the accumulation of reactive oxygen species （ ROS）, and the latter might be related to the accumulation of proline. The results presented here will facilitate the improvement of T. glabrata under hyperosmotic stress.