Plant plasma membrane-bound staphylococcal-like DNases as a novel class of eukaryotic nucleases

BMC Plant Biology

Research Article

Elżbieta Poręba¹  Natalia Wolff²  Przemysław Wojtaszek²  Sławoj Stanisławski²  Michalina Smolarkiewicz²  Krzysztof Leśniewicz² 

[1] Department of Molecular Virology, Institute of Experimental Biology, Adam Mickiewicz University, Poznań, 89 Umultowska St, 61-614, Poznan, Poland;Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznań, 89 Umultowska St, 61-614, Poznan, Poland;

关键词: Staphylococcal-like nuclease;    Programmed cell death;    Plasma-membrane protein;    Senescence;    Myristoylation/palmitylation motif;    ABC transporter;    tRNA synthetase;   

DOI  :  10.1186/1471-2229-12-195

 received in 2012-08-20, accepted in 2012-10-22,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe activity of degradative nucleases responsible for genomic DNA digestion has been observed in all kingdoms of life. It is believed that the main function of DNA degradation occurring during plant programmed cell death is redistribution of nucleic acid derived products such as nitrogen, phosphorus and nucleotide bases. Plant degradative nucleases that have been studied so far belong mainly to the S1-type family and were identified in cellular compartments containing nucleic acids or in the organelles where they are stored before final application. However, the explanation of how degraded DNA components are exported from the dying cells for further reutilization remains open.ResultsBioinformatic and experimental data presented in this paper indicate that two Arabidopsis staphylococcal-like nucleases, named CAN1 and CAN2, are anchored to the cell membrane via N-terminal myristoylation and palmitoylation modifications. Both proteins possess a unique hybrid structure in their catalytic domain consisting of staphylococcal nuclease-like and tRNA synthetase anticodon binding-like motifs. They are neutral, Ca2+-dependent nucleaces showing a different specificity toward the ssDNA, dsDNA and RNA substrates. A study of microarray experiments and endogenous nuclease activity revealed that expression of CAN1 gene correlates with different forms of programmed cell death, while the CAN2 gene is constitutively expressed.ConclusionsIn this paper we present evidence showing that two plant staphylococcal-like nucleases belong to a new, as yet unidentified class of eukaryotic nucleases, characterized by unique plasma membrane localization. The identification of this class of nucleases indicates that plant cells possess additional, so far uncharacterized, mechanisms responsible for DNA and RNA degradation. The potential functions of these nucleases in relation to their unique intracellular location are discussed.

【 授权许可】

CC BY   
© Leśniewicz et al.; licensee BioMed Central Ltd. 2012