UVI31+ Is a DNA Endonuclease That Dynamically Localizes to Chloroplast Pyrenoids in C. reinhardtii

• DOI: 10.1371/journal.pone.0051913
• Publication Date: 2012-12-17T21:55:39Z
• Authors: Manish Shukla; Renu Minda; Himanshu Singh; Srikanth Tirumani; Kandala V. R. Chary; Basuthkar J. Rao
• Keywords: 0303 health sciences; Chloroplasts; Ultraviolet Rays; Science; Q; R; Darkness; Recombinant Proteins; Enzyme Activation; Protein Transport; 03 medical and health sciences; Cell Wall; Gene Expression Regulation, Plant; Medicine; Deoxyribonuclease I; Protein Interaction Domains and Motifs; Chlamydomonas reinhardtii; Research Article; Plant Proteins

UVI31+ is an evolutionarily conserved BolA family protein. In this study we examine the presence, localization and possible functions of this protein in the context of a unicellular alga, Chlamydomonas reinhardtii. UVI31+ in C. reinhardtii exhibits DNA endonuclease activity and is induced upon UV stress. Further, UVI31+ that normally localizes to the cell wall and pyrenoid regions gets redistributed into punctate foci within the whole chloroplast, away from the pyrenoid, upon UV stress. The observed induction upon UV-stress as well as the endonuclease activity suggests plausible role of this protein in DNA repair. We have also observed that UV31+ is induced in C. reinhardtii grown in dark conditions, whereby the protein localization is enhanced in the pyrenoid. Biomolecular interaction between the purified pyrenoids and UVI31+ studied by NMR demonstrates the involvement of the disordered loop domain of the protein in its interaction.