title: Ectopic expression of the RING domain of the Arabidopsis peroxin2 protein partially suppresses the phenotype of the photomorphogenic mutant de-etiolated1.
abstract: The Arabidopsis constitutive photomorphogenic/de-etiolated 1/FUSCA (COP/DET1/FUS) proteins repress photomorphogenesis by degrading positive regulators of photomorphogenesis, such as the transcription factor long hypocotyl5 (HY5). The gain-of-function mutant ted3, which partially suppresses the det1 mutant, contains a missense mutation of a Val-to-Met substitution before the C-terminal RING finger domain of the peroxisomal membrane protein peroxin2 (PEX2). We hypothesized that a truncated PEX2 protein, which only contains the C-terminal RING domain, is initiated by the ted3 mutation and by-passes the function of DET1 in the nucleus. Although we have not been able to detect this hypothetic peptide in vivo, we show in this study that, when fused with a fluorescent protein and overexpressed, the PEX2 RING domain can localize to the nucleus, where it is able to interact with HY5, and PEX2 RING domain overexpression in det1 also partially suppresses the det1 phenotype. Compared with det1, ted3 det1 plants have significantly decreased levels of the HY5 protein and the expression of most of the analyzed HY5 target genes is altered to levels comparable to those in hy5. We conclude that compromised activity of HY5 may have been mainly responsible for the partial reversal of the det1 phenotype in ted3 det1. Our data support the notion that, when appropriately localized, some RING finger domains may be able to achieve neomorphic effects in the cell.
authors.affiliation: Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Mintu
authors.initials: M
authors.lastname: Desai
authors.affiliation: Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Navneet
authors.initials: N
authors.lastname: Kaur
authors.affiliation: Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America; Plant Biology Department, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Jianping
authors.initials: J
authors.lastname: Hu
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017930:Genes, Reporter; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D009024:Morphogenesis / Q000528:radiation effects; D009154:Mutation; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D000074401:Peroxins; D010641:Phenotype; D030821:Plants, Genetically Modified; D025941:Protein Interaction Mapping; D054829:RING Finger Domains / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D036226:Seedlings; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; C088435:DET1 protein, Arabidopsis; C109254:HY5 protein, Arabidopsis; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D000074401:Peroxins; D011993:Recombinant Fusion Proteins; C462525:TED3 protein, Arabidopsis