title: Isolation of three B-box zinc finger proteins that interact with STF1 and COP1 defines a HY5/COP1 interaction network involved in light control of development in soybean.
abstract: LONG HYPOCOTYL5 (HY5) and STF1 (Soybean TGACG-motif binding Factor 1) are two related bZIP transcription factors that play a positive role in photomorphogenesis and hormonal signaling. In this study, we compared full length STF1 and truncated STF1 overexpression lines and found that the C-terminal 133 amino acids (194-306) possess all the HY5-like function in Arabidopsis. The STF1-DC1 mutant (1-306), with a 20 amino acid deletion at the carboxy terminus, failed to complement the hy5 mutant phenotype, which suggests an intact C-terminus is required for STF1 function. To understand the role of the C-terminal domain in photomorphogenesis we used a yeast two-hybrid screen to isolate proteins that bind to the STF1 C-terminus. We isolated three soybean cDNAs encoding the zinc-finger proteins GmSTO, GmSTH, and GmSTH2, which interact with STF1. These proteins belong to a family of B-box zinc finger proteins that include Arabidopsis SALT TOLERANCE (STO) and STO HOMOLOG (STH) and STH2, which play a role in light-dependent development and gene expression. The C-terminal 63 amino acids of STF1, containing a leucine zipper and the two N-terminal B-boxes, contains the domain involved in interactions between STF1 and GmSTO. In addition, we identified an interaction between soybean COP1 (GmCOP1) and GmSTO and GmSTH, as well as STF1, which strongly suggests the presence of a similar regulatory circuit for light signaling in soybean as in Arabidopsis. This study shows that photomorphogenic control requires complex molecular interactions among several different classes of transcription factors such as bZIP, B-box factors, and COP1, a ubiquitin ligase.
authors.affiliation: National Institute of Ecology, 1210 Geumgang-ro, Maseo-myeon, Seocheon-gun, 33657, Republic of Korea; Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
authors.forename: Su Young
authors.initials: SY
authors.lastname: Shin
authors.affiliation: Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
authors.forename: Seong Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
authors.forename: Su Jeong
authors.initials: SJ
authors.lastname: Jeon
authors.affiliation: Gyeongnam Agricultural Research and Extension, Services, Jinju, 52828, Republic of Korea.
authors.forename: Soon Ae
authors.initials: SA
authors.lastname: Sim
authors.affiliation: Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea.
authors.forename: Gyeong Ryul
authors.initials: GR
authors.lastname: Ryu
authors.affiliation: Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, 32611, USA.
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Yoo
authors.affiliation: Department of Bio-Environmental Science, Sunchon National University, Suncheon, 57922, Republic of Korea.
authors.forename: Yong Hwa
authors.initials: YH
authors.lastname: Cheong
authors.affiliation: Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828, Republic of Korea; Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA. Electronic address: jchong@gnu.ac.kr.
authors.forename: Jong Chan
authors.initials: JC
authors.lastname: Hong
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D018076:DNA, Complementary / Q000302:isolation & purification; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D008027:Light; D009154:Mutation / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D000072417:Protein Domains; D054730:Protein Interaction Domains and Motifs; D060066:Protein Interaction Maps; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013025:Glycine max / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects*; D013347:Subcellular Fractions / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics; D016335:Zinc Fingers
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins
keywords: B-box protein; COP1; HY5; STF1; Yeast two hybrid screen; Zinc finger protein