title: Arabidopsis DDB1-CUL4 E3 ligase complexes in det1 salt/osmotic stress resistant germination.
abstract: A key regulatory mechanism in plant growth, development, and stress signaling utilizes E3 ubiquitin ligases, which target a variety of substrates for degradation. DE-ETIOLATED 1 (DET1) forms a complex with DDB1 (DAMAGED DNA BINDING protein 1) and CUL4 (CULLIN 4), and negatively regulates light signaling. Another DDB1-CUL4 complex containing DWA1 and DWA2 (DWD hypersensitive to ABA 1 and 2) has been shown to negatively regulate abscisic acid (ABA) signaling. Since distinct DDB1-CUL4 complexes have been shown to influence each other, we analyzed genetic interactions between DET1 and components of DDB1-CUL4 complexes during seed germination under salt and osmotic stress conditions. det1 germination was resistant to salt and osmotic stress and dwa1 and dwa2 enhanced this phenotype. In contrast, ddb1a partially suppressed the det1 germination phenotype on both salt and mannitol, while ddb1b had no effect. Mutations in DDB2, a DDB1-CUL4 complex component involved in DNA repair, also partially suppressed the det1 germination phenotype while mutants in COP1, another light signaling component, completely suppressed the det1 resistant germination phenotypes. Taken together these data suggest that components of E3 ubiquitin ligase complexes have variable but significant effects on det1 salt/osmotic stress responses.
authors.affiliation: a Department of Biological Sciences , University of Manitoba , Winnipeg , Canada.
authors.forename: V C Dilukshi
authors.initials: VC
authors.lastname: Fernando
authors.affiliation: a Department of Biological Sciences , University of Manitoba , Winnipeg , Canada.
authors.forename: Dana F
authors.initials: DF
authors.lastname: Schroeder
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D044842:Cullin Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000235:genetics / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009997:Osmotic Pressure / Q000502:physiology; D011485:Protein Binding / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; C514806:CULLIN4 protein, Arabidopsis; D044842:Cullin Proteins; C530204:DDB2 protein, Arabidopsis; C088435:DET1 protein, Arabidopsis; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins
keywords: Arabidopsis; COP1; DDB1A/B; DDB2; DET1; DWA1/2; salt/osmotic stress