Dataset Information

Phosphoproteomics of Chlamydomonas reinhardtii in photoautotrophic nitrogen-deficient conditions

ABSTRACT: Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa et al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotrophic N-deficient conditions, tar1-1 cells, with a mutation in the TAR1 gene, maintained higher levels of cell viability and lower levels of hydrogen peroxide generation and accumulated higher levels of TAG and starch compared with those of wild-type (WT) cells with bubbling of air containing 5% carbon dioxide. Transcriptomic analyses suggested that genes involved in the scavenging of reactive oxygen species are not repressed in tar1-1 cells. In contrast, the mating efficiency and mRNA levels of key regulatory genes for gametogenesis, MID, MTD, and FUS, were suppressed in tar1-1 cells. Among the TAR1-dependent phosphopeptides deduced by phosphoproteomic analysis, protein kinases and enzymes related to N assimilation and carbon (C) metabolism are of particular interest. Characterization of these putative downstream factors may elucidate the molecular pathway whereby TAR1 mediates cellular propagation and C and N metabolism in C/N-imbalanced stress conditions.

ORGANISM(S): Cellular Organisms

SUBMITTER: Hirofumi Nakagami

PROVIDER: PXD012311 | JPOST Repository | Mon Jan 14 00:00:00 GMT 2019

REPOSITORIES: jPOST

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Algal Protein Kinase, Triacylglycerol Accumulation Regulator 1, Modulates Cell Viability and Gametogenesis in Carbon/Nitrogen-Imbalanced Conditions.

Shinkawa Haruka H Kajikawa Masataka M Nomura Yuko Y Ogura Mayu M Sawaragi Yuri Y Yamano Takashi T Nakagami Hirofumi H Sugiyama Naoyuki N Ishihama Yasushi Y Kanesaki Yu Y Yoshikawa Hirofumi H Fukuzawa Hideya H

Plant & cell physiology 20190401 4

Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa etï¿½al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotr ...[more]

PMID: 30668822

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