title: Characterization and functional analysis of four HYH splicing variants in Arabidopsis hypocotyl elongation.
abstract: Arabidopsis thaliana LONG HYPOCOTYL5 (HY5) is a positive regulator of the light signaling pathway. The hy5 mutant has an elongated hypocotyl in all light conditions, whereas the hy5 homolog (hyh) mutant has a very weak phenotype, but only in blue light. However, overexpression of HYH rescues the elongated hypocotyl phenotype in the hy5 null mutant. Here, we report the identification of four HYH splicing variants in Arabidopsis. Alternative splicing in the 5' region of the HYH gene occurred such that the proteins encoded by all four HYH variants retained their bZIP domain. In hypocotyl tissue, transcript levels of HYH.2, HYH.3, and HYH.4 were higher than those of HYH.1. Like HY5, all HYH variants were induced by light. Functional analysis of the four HYH variants, based on their abilities to complement the hy5 mutant, indicated that they have similar roles in hypocotyl development, and may function redundantly with HY5. Our results indicate that the bZIP domain in HYH is critical for the function of four variants in the compensation of hy5 mutant in hypocotyl development. Additionally, while HY5/HYH is found in plant species ranging from green algae to flowering plants, the potential alternative splicing events are distinct in different species, with certain HYH variants found with greater frequency in some species than others.
authors.affiliation: Laboratory of Chinese Herbal Pharmacology, Oncology Center, Renmin Hospital, Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Shiyan 442000, China; Laboratory of Medicinal Plant, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Li
authors.affiliation: Laboratory of Medicinal Plant, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China.
authors.forename: Lanlan
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Laboratory of Medicinal Plant, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China.
authors.forename: Jingxuan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Laboratory of Medicinal Plant, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Lv
authors.affiliation: Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, Shandong 266101, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Liu
authors.affiliation: Laboratory of Chinese Herbal Pharmacology, Oncology Center, Renmin Hospital, Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Shiyan 442000, China.
authors.forename: Xuanbin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Biology, Faculty of Sciences, University of Pecs, Hungary.
authors.forename: Gergo
authors.initials: G
authors.lastname: Palfalvi
authors.affiliation: Key Laboratory of Ministry of Education for Medicinal Plant Resource and Natural Pharmaceutical Chemistry, National Engineering Laboratory for Resource Developing of Endangered Chinese Crude Drugs in Northwest of China, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. Electronic address: guodong_wang@snnu.edu.cn.
authors.forename: Guodong
authors.initials: G
authors.lastname: Wang
authors.affiliation: Laboratory of Medicinal Plant, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China. Electronic address: zhangyonghong0622@163.com.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D018546:Hypocotyl / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010641:Phenotype; D012326:RNA Splicing
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C457459:HYH protein, Arabidopsis
keywords: Alternative splicing; Arabidopsis; HY5; HYH; Hypocotyl development; Splicing variant