title: The OsCYP19-4 Gene Is Expressed as Multiple Alternatively Spliced Transcripts Encoding Isoforms with Distinct Cellular Localizations and PPIase Activities under Cold Stress.
abstract: Alternative splicing (AS) is an important molecular mechanism by which single genes can generate multiple mRNA isoforms. We reported previously that, in Oryza sativa, the cyclophilin 19-4 (OsCYP19-4.1) transcript was significantly upregulated in response to cold stress, and that transgenic plants were cold tolerant. Here we show that, under cold stress, OsCYP19-4 produces eight transcript variants by intron retention and exon skipping, resulting in production of four distinct protein isoforms. The OsCYP19-4 AS isoforms exhibited different cellular localizations in the epidermal cells: in contrast to OsCYP19-4.1, the OsCYP19-4.2 and OsCYP19-4.3 proteins were primarily targeted to guard and subsidiary cells, whereas OsCYP19-4.5, which consists largely of an endoplasmic reticulum (ER) targeting signal, was co-localized with the RFP-BiP marker in the ER. In OsCYP19-4.2, the key residues of the PPIase domain are altered; consistent with this, recombinant OsCYP19-4.2 had significantly lower PPIase activity than OsCYP19-4.1 in vitro. Specific protein-protein interactions between OsCYP19-4.2/3 and AtRCN1 were verified in yeast two-hybrid (Y2H) and bimolecular fluoresence complementation (BiFC assays), although the OsCYP19-4 isoforms could not bind each other. Based on these results, we propose that two OsCYP19-4 AS isoforms, OsCYP19-4.2 and OsCYP19-4.3, play roles linking auxin transport and cold stress via interactions with RCN1.
authors.affiliation: Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon 34113, Korea. lar1027@kribb.re.kr.|Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. lar1027@kribb.re.kr.
authors.forename: Areum
authors.initials: A
authors.lastname: Lee
authors.affiliation: Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. sosimsimgo2016@gmail.com.
authors.forename: Sang Sook
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. jwy95@kribb.re.kr.
authors.forename: Won Yong
authors.initials: WY
authors.lastname: Jung
authors.affiliation: Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. hjpark@kribb.re.kr.
authors.forename: Hyun Ji
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. lbr217@kribb.re.kr.
authors.forename: Bo Ra
authors.initials: BR
authors.lastname: Lim
authors.affiliation: Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. hyuns@kribb.re.kr.
authors.forename: Hyun-Soon
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Pharmacology, College of Medicine, Seonam University, Namwon 55724, Korea. secmeta2@seonam.ac.kr.
authors.forename: Jun Cheul
authors.initials: JC
authors.lastname: Ahn
authors.affiliation: Biosystems and Bioengineering Program, University of Science and Technology (UST), Daejeon 34113, Korea. hscho@kribb.re.kr.|Molecular Biofarming Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea. hscho@kribb.re.kr.
authors.forename: Hye Sun
authors.initials: HS
authors.lastname: Cho
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D001141:Aromatase / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D058639:Cold-Shock Response / Q000235:genetics*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D015151:Immunoblotting; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000235:genetics / Q000378:metabolism*; D060066:Protein Interaction Maps; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020798:Two-Hybrid System Techniques
chemical_list: D020033:Protein Isoforms; D001141:Aromatase; D019696:Peptidylprolyl Isomerase
keywords: OsCYP19-4; PPIase activity; RCN1 interactor; alternative splicing; cold stress; isoform