title: Knockout of RP2 decreases GRK1 and rod transducin subunits and leads to photoreceptor degeneration in zebrafish.
abstract: Retinitis pigmentosa (RP) affects about 1.8 million individuals worldwide. X-linked retinitis pigmentosa (XLRP) is one of the most severe forms of RP. Nearly 85% of XLRP cases are caused by mutations in the X-linked retinitis pigmentosa 2 (RP2) and RPGR. RP2 has been considered to be a GTPase activator protein for ARL3 and to play a role in the traffic of ciliary proteins. The mechanism of how RP2 mutations cause RP is still unclear. In this study, we generated an RP2 knockout zebrafish line using transcription activator-like effector nuclease technology. Progressive retinal degeneration could be observed in the mutant zebrafish. The degeneration of rods' outer segments (OSs) is predominant, followed by the degeneration of cones' OS. These phenotypes are similar to the characteristics of RP2 patients, and also partly consistent with the phenotypes of RP2 knockout mice and morpholino-mediated RP2 knockdown zebrafish. For the first time, we found RP2 deletion leads to decreased protein levels and abnormal retinal localizations of GRK1 and rod transducin subunits (GNAT1 and GNB1) in zebrafish. Furthermore, the distribution of the total farnesylated proteins in zebrafish retina is also affected by RP2 ablation. These molecular alterations observed in the RP2 knockout zebrafish might probably be responsible for the gradual loss of the photoreceptors' OSs. Our work identified the progression of retinal degeneration in RP2 knockout zebrafish, provided a foundation for revealing the pathogenesis of RP caused by RP2 mutations, and would help to develop potential therapeutics against RP in further studies.
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Jiaxiang
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Yu
authors.affiliation: Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK and and.
authors.forename: Rakesh Kotapati
authors.initials: RK
authors.lastname: Raghupathy
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Xiliang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Yayun
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Chang
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Mi
authors.initials: M
authors.lastname: Huang
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Liao
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China.
authors.forename: Jiuxiang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Translational Medicine, Zhejiang University, 268 Kaixuan Road, Zhongxin Beilou, Hangzhou, 310029 Zhejiang, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zou
authors.affiliation: Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK and and.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Shu
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China, lium@hust.edu.cn zh_tang@hust.edu.cn.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, PR China, lium@hust.edu.cn zh_tang@hust.edu.cn.
authors.forename: Mugen
authors.initials: M
authors.lastname: Liu
mesh_terms: D000818:Animals; D005136:Eye Proteins; D051606:G-Protein-Coupled Receptor Kinase 1 / Q000235:genetics / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D040181:Genetic Diseases, X-Linked / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism* / Q000473:pathology; D012174:Retinitis Pigmentosa / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015293:Transducin / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000172:deficiency*
chemical_list: D005136:Eye Proteins; C559526:RP2 protein, zebrafish; D029961:Zebrafish Proteins; D051606:G-Protein-Coupled Receptor Kinase 1; D015293:Transducin