title: DWD HYPERSENSITIVE TO UV-B 1 is negatively involved in UV-B mediated cellular responses in Arabidopsis.
abstract: Among T-DNA insertion mutants of various cullin4-RING ubiquitin E3 ligase (CRL4) substrate receptors, one mutant that exhibits enhanced sensitivity in response to ultraviolet-B (UV-B) illumination has been isolated and its corresponding gene has been named DWD HYPERSENSITIVE TO UV-B 1 (DHU1) in Arabidopsis. dhu1 lines showed much shorter hypocotyls than those in wild type under low doses of UV-B. Other light did not alter hypocotyl growth patterns in dhu1, indicating the hypersensitivity of dhu1 is restricted to UV-B. DHU1 was upregulated by more than two times in response to UV-B application of 1.5 μmol m(-2) s(-1), implying its possible involvement in UV-B signaling. DHU1 is able to bind to DDB1, an adaptor of CRL4; accordingly, DHU1 is thought to act as a substrate receptor of CRL4. Microarray data generated from wild-type and dhu1 under low doses of UV-B revealed that 209 or 124 genes were upregulated or downregulated by more than two times in dhu1 relative to wild type, respectively. About 23.4 % of the total upregulated genes in dhu1 were upregulated by more than five times in response to UV-B based on the AtGenExpress Visualization Tool data, while only about 1.4 % were downregulated to the same degree by UV-B, indicating that loss of DHU1 led to the overall enhancement of the upregulation of UV-B inducible genes. dhu1 also showed altered responsiveness under high doses of UV-B. Taken together, these findings indicate that DHU1 is a potent CRL4 substrate receptor that may function as a negative regulator of UV-B response in Arabidopsis.
authors.affiliation: Department of Biology Education, Pusan National University, Pusan, 609-735, Korea.
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Hani
authors.initials: H
authors.lastname: Kim
authors.forename: Kyoung-In
authors.initials: KI
authors.lastname: Seo
authors.forename: Soon-Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Sunglan
authors.initials: S
authors.lastname: Chung
authors.forename: Xi
authors.initials: X
authors.lastname: Huang
authors.forename: Panyu
authors.initials: P
authors.lastname: Yang
authors.forename: Xing Wang
authors.initials: XW
authors.lastname: Deng
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008954:Models, Biological; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D030821:Plants, Genetically Modified; D011485:Protein Binding; D015398:Signal Transduction; D013312:Stress, Physiological; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; C000594929:DWD HYPERSENSITIVE TO UV-B 1 protein, Arabidopsis; D002734:Chlorophyll; D000217:Acyltransferases; C491135:AT5G13930 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases