title: RAD5a ubiquitin ligase is involved in ubiquitination of Arabidopsis thaliana proliferating cell nuclear antigen.
abstract: The proliferating cell nuclear antigen (PCNA) is post-translationally modified by ubiquitin in yeast and mammalian cells. It is widely accepted that in yeast mono- and polyubiquitinated PCNA is involved in distinct pathways of DNA postreplication repair. This study showed an interaction between plant ubiquitin and PCNA in the plant cell. Using different approaches, it was demonstrated that Arabidopsis RAD5a ubiquitin ligase is involved in the post-translational modification of plant PCNA. A detailed analysis of the properties of selected Arabidopsis ubiquitin-conjugating enzymes (AtUBC) has shown that a plant homologue of yeast RAD6 (AtUBC2) is sufficient to monoubiquitinate AtPCNA in the absence of ubiquitin ligase. Using different combinations of selected AtUBC proteins together with AtRAD5a, it was demonstrated that plants have potential to use different pathways to ubiquitinate PCNA. The analysis of Arabidopsis PCNA1 and PCNA2 did not demonstrate substantial differences in the ubiquitination pattern between these two proteins. The major ubiquitination target of Arabidopsis PCNA, conserved in eukaryotes, is lysine 164. Taken together, the presented results clearly demonstrate the involvement of Arabidopsis UBC and RAD5a proteins in the ubiquitination of plant PCNA at lysine 164. The data show the complexity of the plant ubiquitination system and open new questions about its regulation in the plant cell.
authors: Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, Poland. wojciech.strzalka@uj.edu.pl
authors: Wojciech
authors: W
authors: Strzalka
authors: Filip
authors: F
authors: Bartnicki
authors: Katarzyna
authors: K
authors: Pels
authors: Agata
authors: A
authors: Jakubowska
authors: Toshiki
authors: T
authors: Tsurimoto
authors: Katsunori
authors: K
authors: Tanaka
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D008239:Lysine / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D059828:Plant Cells / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; D018809:Proliferating Cell Nuclear Antigen; C561786:RAD5a protein, Arabidopsis; D011993:Recombinant Fusion Proteins; D025801:Ubiquitin; D044763:Ubiquitin-Conjugating Enzymes; D008239:Lysine