De-Etiolated 1 and Damaged DNA Binding Protein 1 Interact to Regulate Arabidopsis Photomorphogenesis

Abstract

DET1 and DDB1 interact both biochemically and genetically. In animal cells, DDB1 interacts with histone acetyltransferase complexes. The DET1/DDB1 complex may regulate gene expression in response to light via recruitment of HAT activity. Thus, DET1, whose sequence is conserved in both animals and plants, may play a direct role in the regulation of many genes.

The E3 Ubiquitin Ligase Gene Family in Plants: Regulation by Degradation

“…Currently, knowledge from human allowed identifying plant orthologs for all the subunits of the human CUL4-DDB1 complexes (Supplementary Table S1). Two highly related DDB1 genes, named DDB1a and DDB1b were found in Arabidopsis [55]; other subunits are DET1 [55], COP10, COP1 [56] and DDB2 [57].…”

“…Although arrest at the heart stage was predominant, block of embryogenesis occurring at multiple stages of embryo development indicated a general growth inhibition of the embryo. CUL4-DDB1 complex also appears essential, being the ddb1b mutation embryo lethal, although Arabidopsis contains two highly related DDB1 proteins [55]. According to RBX1 involvement in the formation of SCF, CUL3-BTB and CUL4-DDB1 complexes, severe phenotypes were observed for Arabidopsis RBX1 dsRNA lines, consistently with the suppression level [34], including the block of seedling development, death of young seedlings, or severe dwarf phenotypes.…”

Signalling for developmental plasticity

“…For example, COP1, DE-ETIOLATED 1 (DET1, Accession number L33695) [36,37], and COP9 (Accession number L33695) [38] are nuclear proteins that repress photomorphogenesis in darkness and have animal counterparts. COP1 promotes ubiquitin-mediated proteolysis of a subset of positive regulators, including HY5 [17] and LONG AFTER FAR-RED (LAF1, Accession number Z95744) [39].…”

“…DET1 binds in vitro to nonacetylated N-terminal tails of the core histone H2B in the context of the nucleosome and interacts with DAMAGED DNA BINDING PROTEIN 1 (DDB1, Accession number NP_192451) [36,37]. The DET1 -DDB1 complex could interact with chromatin via association with the nonacetylated H2B tail, negatively regulating transcription.…”

“…The DET1 -DDB1 complex could interact with chromatin via association with the nonacetylated H2B tail, negatively regulating transcription. Light could recruit histone acetyltransferase via interaction with DDB1, acetylate histone, release the DET1 complex and therefore allow the expression of photomorphogenic genes [36,37]. DDB1 has recently been reported in complexes containing the COP9 signalosome in fibroblasts [40].…”