title: The SNW Domain of SKIP Is Required for Its Integration into the Spliceosome and Its Interaction with the Paf1 Complex in Arabidopsis.
abstract: SKIP is a conserved protein from yeasts to plants and humans. In plant cells, SKIP is a bifunctional regulator that works in the nucleus as a splicing factor by integrating into the spliceosome and as a transcriptional activator by interacting with the Paf1 complex. In this study, we identified two nuclear localization signals in SKIP and confirmed that each is sufficient to target SKIP to the nucleus. The SNW domain of SKIP is required for both its function as a splicing factor by promoting integration into the spliceosome in response to stress, and its function as a transcriptional activator by controlling its interaction with the Paf1 complex to participate in flowering. Truncated proteins that included the SNW domain and the N- or C-terminus of SKIP were still able to carry out the functions of the full-length protein in gene splicing and transcriptional activation in Arabidopsis. In addition, we found that SKIP undergoes 26S proteasome-mediated degradation, and that the C-terminus of SKIP is required to maintain the stability of the protein in plant cells. Together, our findings demonstrate the structural domain organization of SKIP and reveal the core domains and motifs underlying SKIP function in plants.
authors.affiliation: College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei 050021, China; Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Congcong
authors.initials: C
authors.lastname: Xia
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Jinlin
authors.initials: J
authors.lastname: Feng
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Yang
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Fangming
authors.initials: F
authors.lastname: Wu
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China.
authors.forename: Legong
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, Beijing 100048, China; College of Life Sciences, Capital Normal University, Beijing 100048, China. Electronic address: ligeng.ma@cnu.edu.cn.
authors.forename: Ligeng
authors.initials: L
authors.lastname: Ma
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D000072417:Protein Domains; D017381:Spliceosomes / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C549998:SKIP protein, Arabidopsis; D014157:Transcription Factors; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease
keywords: 26S proteasome-mediated degradation; Paf1 complex; SKIP; core domain and motif; nuclear localization signal; spliceosome