Ubiquitin-conjugated degradation of golden 2-like transcription factor is mediated by CUL4-DDB1-based E3 ligase complex in tomato.
CULLIN4-RING ubiquitin ligases (CRL4s) as well as their targets are fundamental regulators functioning in many key developmental and stress responses in eukaryotes. In tomato (Solanum lycopersicum), molecular cloning has revealed that the underlying genes of natural spontaneous mutations high pigment 1 (hp1), high pigment 2 (hp2) and uniform ripening (u) encode UV-DAMAGED DNA BINDING PROTEIN 1 (DDB1), DE-ETIOLATED 1 (DET1) and GOLDEN 2-LIKE (GLK2), respectively. However, the molecular basis of the opposite actions of tomato GLK2 vs CUL4-DDB1-DET1 complex on regulating plastid level and fruit quality remains unknown. Here, we provide molecular evidence showing that the tomato GLK2 protein is a substrate of the CUL4-DDB1-DET1 ubiquitin ligase complex for the proteasome degradation. SlGLK2 is degraded by the ubiquitin-proteasome system, which is mainly determined by two lysine residues (K11 and K253). SlGLK2 associates with the CUL4-DDB1-DET1 E3 complex in plant cells. Genetically impairing CUL4, DDB1 or DET1 results in a retardation of SlGLK2 degradation by the 26S proteasome. These findings are relevant to the potential of nutrient accumulation in tomato fruit by mediating the plastid level and contribute to a deeper understanding of an important regulatory loop, linking protein turnover to gene regulation.
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.
Xiaofeng
X
Tang
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Min
M
Miao
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Xiangli
X
Niu
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Danfeng
D
Zhang
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Xulv
X
Cao
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Xichen
X
Jin
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Yunye
Y
Zhu
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Youhong
Y
Fan
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Hongtao
H
Wang
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Ying
Y
Liu
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.
Yuan
Y
Sui
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Department of Plant, Soil, and Entomological Sciences, University of Idaho, Moscow, ID, 83844, USA.
Wenjie
W
Wang
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Boyce Thompson Institute for Plant Research, Cornell University, Tower Road, Ithaca, NY, 14853, USA.
Anquan
A
Wang
Department of Plant, Soil, and Entomological Sciences, University of Idaho, Moscow, ID, 83844, USA.
Fangming
F
Xiao
Boyce Thompson Institute for Plant Research, Cornell University, Tower Road, Ithaca, NY, 14853, USA.
Jim
J
Giovannoni
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.
Yongsheng
Y
Liu
D015536:Down-Regulation; D018551:Solanum lycopersicum / Q000378:metabolism*; D059828:Plant Cells / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D055550:Protein Stability; D059748:Proteolysis; D014157:Transcription Factors / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D025801:Ubiquitin / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination
D010940:Plant Proteins; D014157:Transcription Factors; D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex
26S proteasome; cullin4-DDB1-DET1 complex; golden 2-like transcription factor; tomato (Solanum lycopersicum); ubiquitin-conjugated degradation