Proteomic Analysis in Nitrogen-Deprived Isochrysis galbana during Lipid Accumulation

PLoS One

Ling Li¹  Jianguo Liu²  Pingping Song² 

[1] Graduate University of Chinese Academy of Sciences, Beijing, China;Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China

关键词: Lipids;    Fatty acids;    Lipid metabolism;    Algae;    Protein expression;    Sulfur;    Chloroplasts;    Enzymes;   

DOI  :  10.1371/journal.pone.0082188

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

The differentially co-expressed proteins in N-deprived and N-enriched I. galbana were comparatively analyzed by using two dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight-mass spectrometry (MALDI-TOF/TOF-MS) with the aim of better understanding lipid metabolism in this oleaginous microalga. Forty-five of the 900 protein spots showed dramatic changes in N-deprived I. galbana compared with the N-enriched cells. Of these, 36 protein spots were analyzed and 27 proteins were successfully identified. The identified proteins were classified into seven groups by their molecular functions, including the proteins related to energy production and transformation, substance metabolism, signal transduction, molecular chaperone, transcription and translation, immune defense and cytoskeleton. These altered proteins slowed cell growth and photosynthesis of I. galbana directly or indirectly, but at the same time increased lipid accumulation. Eight key enzymes involved in lipid metabolism via different pathways were identified as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK), enolase, aspartate aminotransferase (AST), fumarate hydratase (FH), citrate synthase (CS), O-acetyl-serine lyase (OAS-L) and ATP sulfurylase (ATPS). The results suggested that the glycolytic pathway and citrate transport system might be the main routes for lipid anabolism in N-deprived I. galbana, and that the tricarboxylic acid (TCA) cycle, glyoxylate cycle and sulfur assimilation system might be the major pathways involved in lipid catabolism.

【 授权许可】

CC BY