Quantitative proteomics shows extensive remodeling induced by nitrogen limitation in prochlorococcus marinus SS120

TitleQuantitative proteomics shows extensive remodeling induced by nitrogen limitation in prochlorococcus marinus SS120
Publication TypeJournal Article
Year of Publication2017
AuthorsDomínguez-Martín MAgustina, Gómez-Baena G, Díez J, López-Grueso MJosé, Beynon RJ, García-Fernández JManuel
Secondary AuthorsHuber JA
JournalmSystems
Volume2
Paginatione00008–17
Date Publishedjun
ISSN2379-5077
KeywordsRCC156
Abstract

Prochlorococcus requires the capability to accommodate to environmental changes in order to proliferate in oligotrophic oceans, in particular regarding nitrogen availability. A precise knowledge of the composition and changes in the proteome can yield fundamental insights into such a response. Here we report a detailed proteome analysis of the important model cyanobacterium Prochlorococcus marinus SS120 after treatment with azaserine, an inhibitor of ferredoxin-dependent glutamate synthase (GOGAT), to simulate extreme nitrogen starvation. In total, 1,072 proteins, corresponding to 57% of the theoretical proteome, were identified—the maximum proteome coverage obtained for any Prochlorococcus strain thus far. Spectral intensity, calibrated quantification by the Hi3 method, was obtained for 1,007 proteins. Statistically significant changes ( P value of ¡0.05) were observed for 408 proteins, with the majority of proteins (92.4%) downregulated after 8 h of treatment. There was a strong decrease in ribosomal proteins upon azaserine addition, while many transporters were increased. The regulatory proteins P II and PipX were decreased, and the global nitrogen regulator NtcA was upregulated. Furthermore, our data for Prochlorococcus indicate that NtcA also participates in the regulation of photosynthesis. Prochlorococcus responds to the lack of nitrogen by slowing down translation, while inducing photosynthetic cyclic electron flow and biosynthesis of proteins involved in nitrogen uptake and assimilation.

URLhttp://msystems.asm.org/lookup/doi/10.1128/mSystems.00008-17
DOI10.1128/mSystems.00008-17