Fig. 3

The protein–protein interaction (PPI) network of the two-component system, their response regulators and the up- and downregulated proteins found in the Synechocystis ∆Hik28 (MT) strain under A low-temperature stress, B high-temperature stress, C combined low-temperature and nitrogen-depletion stress and D combined high-temperature and nitrogen-depletion stress. The PPI network of the regulated proteins in metabolic pathways is illustrated in the boxes bounded by the dotted lines. The up- and downregulated proteins are shown in red and blue letters, respectively