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
- National Institute of Ecology, 1210 Geumgang-ro, Maseo-myeon, Seocheon-gun, 33657 (Korea, Republic of)
- Division of Life Science, Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Gyeongnam, 52828 (Korea, Republic of)
- Gyeongnam Agricultural Research and Extension, Services, Jinju, 52828 (Korea, Republic of)
- Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, 32611 (United States)
- Department of Bio-Environmental Science, Sunchon National University, Suncheon, 57922 (Korea, Republic of)
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. - Highlights: • STF1 interact with GmSTO, GmSTH and GmSTH2. • The bZIP transcription factor STF1 requires an intact C-terminal domain for STF1 function. • STF1 and GmSTO are nuclear proteins.
- OSTI ID:
- 22696601
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 478, Issue 3; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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