Prof. Dr. Martin Hagemann

The role of small proteins in metabolic regulation of cyanobacteria

Rostock University (Germany), Plant Physiology

The cyanobacterium Synechocystis sp. strain PCC 6803 serves as the model for oxygenic photosynthesis as well as metabolic regulation within this environmentally important group of primary producers. Recently, previously unknown transcripts were identified among them many could encode for small proteins/peptides. Within SPP2002, we will initiate the functional annotation of small proteins among Synechocystis. Particularly, we will concentrate on three small proteins, among them two have been already verified, for their potential to exhibit regulatory functions on primary metabolism in Synechocystis. Candidate genes were selected by genome-wide co-expression/co-localization analyses, which were done by our cooperation partner W. R. Hess at the University of Freiburg. Biochemical and physiological analysis using mutants (knock out and selected site-specific mutants abolishing the small protein expression) and strains ectopically expressing the small proteins will reveal if they are really functionally important. We hypothesize that these small proteins could directly or indirectly regulate specific enzymes such as glyceraldehyde 3-phosphate dehydrogenase und aconitate dehydratase and participate in the regulation of primary metabolism. Based on this screening, attempts will be started to define the molecular mechanisms for their action.

References related to the topic:

  1. Klähn S, Schaal C, Georg J, Baumgartner D, Knippen G, Hagemann M, Muro-Pastor AM, Hess WR (2015b) The regulatory RNA NsiR4 controls nitrogen assimilation in cyanobacteria by targeting glutamine synthetase inactivating factor IF7. Proc Natl Acad Sci USA 112:E6243-E6252
  2. Klähn S., Höhne A., Simon E., Hagemann M (2010) The gene ssl3076 encodes a protein mediating the salt-induced expression of ggpS for the biosynthesis of the compatible solute glucosylglycerol in Synechocystis sp. strain PCC 6803. J Bacteriol 192:4403-4012
  3. Kopf M, Klähn S, Pade N, Weingärtner M, Hagemann M, Voß B, Hess WR (2014) Comparative genome analysis of the closely related Synechocystis strains PCC 6714 and PCC 6803. DNA Res 21:255-266
  4. Orf I, Klähn S, Schwarz D, Frank M, Hess WR, Hagemann M, Kopka J (2015) Integrated analysis of engineered carbon limitation in a quadruple CO2/HCO3-uptake mutant of Synechocystis sp. PCC 6803. Plant Physiol 169:1787-1806
  5. Schwarz D, Schubert H, Georg J, Hess WR, Hagemann M (2013) The gene sml0013 of Synechocystis sp. strain PCC 6803 encodes for a novel subunit of the NDH1 complex that is ubiquitous distributed among cyanobacteria. Plant Physiol 163:1991-1202

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