A novel Ca2+-binding protein influences photosynthetic electron transport in Anabaena sp. PCC 7120

Publication date: Available online 27 April 2019Source: Biochimica et Biophysica Acta (BBA) - BioenergeticsAuthor(s): Julia Walter, Khaled A. Selim, Francisco Leganés, Francisca Fernández-Piñas, Ute C. Vothknecht, Karl Forchhammer, Eva-Mari Aro, Peter J. GollanAbstractCa2+ is a potent signalling molecule that regulates many cellular processes. In cyanobacteria, Ca2+ has been linked to cell growth, stress response and photosynthesis, and to the development of specialist heterocyst cells in certain nitrogen-fixing species. Despite this, the pathways of Ca2+ signal transduction in cyanobacteria are poorly understood, and very few protein components are known. The current study describes a previously unreported Ca2+-binding protein which was called the Ca2+ Sensor EF-hand (CSE), which is conserved in filamentous, nitrogen-fixing cyanobacteria. CSE is shown to bind Ca2+, which induces a conformational change in the protein structure. Poor growth of a strain of Anabaena sp. PCC 7120 overexpressing CSE was attributed to diminished photosynthetic performance. Transcriptomics, biophysics and proteomics analyses revealed modifications in the light-harvesting phycobilisome and photosynthetic reaction centre protein complexes.Graphical abstract

Source: Biochimica et Biophysica Acta (BBA) Bioenergetics - April 27, 2019 Category: Biochemistry Source Type: research