caa a22 4500 467895384 CHVBK 20180406152802.0 cr unu---uuuuu 170328e20060901xx s 000 0 eng 10.1007/s11103-006-9019-9 doi (NATIONALLICENCE)springer-10.1007/s11103-006-9019-9 Molecular Control of Nuclear and Subnuclear Targeting of the Plant CDK Inhibitor ICK1 and ICK1-Mediated Nuclear Transport of CDKA [Elektronische Daten] [Yongming Zhou, Hesheng Niu, Federica Brandizzi, Larry Fowke, Hong Wang] ICK1 is the first member of a family of plant cyclin-dependent kinase (CDK) inhibitors. It has been shown that ICK1 is localized in the nuclei of transgenic Arabidopsis plants. Since cellular localization is important for the functions of cell cycle regulators, a comprehensive analysis was undertaken to identify specific sequences regulating the cellular localization of ICK1. Deletion and site-specific mutants fused to the green fluorescent protein (GFP) were used in transgenic Arabidopsis plants and transfected tobacco cells. Surprisingly, three separate sequences in the N-terminal, central and C-terminal regions of ICK1 could independently confer nuclear localization of the GFP fusion proteins. The central nuclear localization signal NLSICK1 could transport the much larger GUS (β-glucuronidase)-GFP fusion protein into nuclei, while the other two sequences were unable to. These results suggest that NLSICK1 is a strong NLS that actively transports the fusion protein into nuclei, while the other two sequences are either a weaker NLS or confer the nuclear localization of GFP indirectly. It was further observed that the N-terminal sequence specifies a punctate pattern of subnuclear localization, while the C-terminal sequence suppresses it. Furthermore, co-expression of ICK1 and Arabidopsis CDKA, tagged with different GFP variants, showed that ICK1 could mediate the transport of CDKA into nuclei while a mutant ICK11-162 that does not interact with CDKA lost this ability. These results illustrate how the nuclear localization of ICK1 is regulated and also suggest a possible role of ICK1 in regulating the cellular distribution of CDKA. Springer Science+Business Media B.V., 2006 Arabidopsis nationallicence CDK inhibitor nationallicence Cell cycle nationallicence ICK1 nationallicence Nuclear localization nationallicence Subnuclear domain nationallicence CDK : cyclin-dependent kinase nationallicence CFP : cyan fluorescent protein nationallicence DAPI : diamidino-2-phenylindole nationallicence GFP : green fluorescent protein nationallicence GUS : β-glucuronidase nationallicence ICK : inhibitor of cyclin-dependent kinase nationallicence KRP : kip-related protein nationallicence NLS : nuclear localization signal nationallicence YFP : yellow fluorescent protein nationallicence Zhou Yongming Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut Niu Hesheng Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut Brandizzi Federica Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut Fowke Larry Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut Wang Hong Department of Biochemistry, University of Saskatchewan, S7N 5E5, Saskatoon, Canada aut Plant Molecular Biology Kluwer Academic Publishers 62/1-2(2006-09-01), 261-278 0167-4412 62:1-2<261 2006 62 11103 https://doi.org/10.1007/s11103-006-9019-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11103-006-9019-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhou Yongming Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut NATIONALLICENCE 700 1- Niu Hesheng Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut NATIONALLICENCE 700 1- Brandizzi Federica Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut NATIONALLICENCE 700 1- Fowke Larry Department of Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E2 aut NATIONALLICENCE 700 1- Wang Hong Department of Biochemistry, University of Saskatchewan, S7N 5E5, Saskatoon, Canada aut NATIONALLICENCE 773 0- Plant Molecular Biology Kluwer Academic Publishers 62/1-2(2006-09-01), 261-278 0167-4412 62:1-2<261 2006 62 11103 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer