title: Pathogenic mutations in retinitis pigmentosa 2 predominantly result in loss of RP2 protein stability in humans and zebrafish.
abstract: Mutations in retinitis pigmentosa 2 (RP2) account for 10-20% of X-linked retinitis pigmentosa (RP) cases. The encoded RP2 protein is implicated in ciliary trafficking of myristoylated and prenylated proteins in photoreceptor cells. To date >70 mutations inRP2have been identified. How these mutations disrupt the function of RP2 is not fully understood. Here we report a novel in-frame 12-bp deletion (c.357_368del, p.Pro120_Gly123del) in zebrafishrp2The mutant zebrafish shows reduced rod phototransduction proteins and progressive retinal degeneration. Interestingly, the protein level of mutant Rp2 is almost undetectable, whereas its mRNA level is near normal, indicating a possible post-translational effect of the mutation. Consistent with this hypothesis, the equivalent 12-bp deletion in humanRP2markedly impairs RP2 protein stability and reduces its protein level. Furthermore, we found that a majority of theRP2pathogenic mutations (including missense, single-residue deletion, and C-terminal truncation mutations) severely destabilize the RP2 protein. The destabilized RP2 mutant proteins are degraded via the proteasome pathway, resulting in dramatically decreased protein levels. The remaining non-destabilizing mutations T87I, R118H/R118G/R118L/R118C, E138G, and R211H/R211L are suggested to impair the interaction between RP2 and its protein partners (such as ARL3) or with as yet unknown partners. By utilizing a combination ofin silico,in vitro, andin vivoapproaches, our work comprehensively indicates that loss of RP2 protein structural stability is the predominating pathogenic consequence for mostRP2mutations. Our study also reveals a role of the C-terminal domain of RP2 in maintaining the overall protein stability.
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Fei
authors.identifier: 0000-0002-0310-1072
authors.initials: F
authors.lastname: Liu
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Yayun
authors.initials: Y
authors.lastname: Qin
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Yu
authors.affiliation: MRC Human Genetics Unit/Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom, and.
authors.forename: Dinesh C
authors.initials: DC
authors.lastname: Soares
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Lifang
authors.initials: L
authors.lastname: Yang
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Weng
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Li
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Gao
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Zhaojing
authors.initials: Z
authors.lastname: Lu
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Xuebin
authors.initials: X
authors.lastname: Hu
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Xiliang
authors.initials: X
authors.lastname: Liu
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Jing Yu
authors.initials: JY
authors.lastname: Liu
authors.affiliation: Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Shu
authors.affiliation: From the 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, Wuhan, Hubei 430074, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Tang
authors.affiliation: From the 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, Wuhan, Hubei 430074, China, lium@hust.edu.cn.
authors.forename: Mugen
authors.initials: M
authors.lastname: Liu
mesh_terms: D000818:Animals; D001483:Base Sequence; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D000072417:Protein Domains; D055550:Protein Stability; D012162:Retinal Degeneration / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005136:Eye Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C072178:RP2 protein, human; C559526:RP2 protein, zebrafish; D029961:Zebrafish Proteins; D019204:GTP-Binding Proteins
keywords: RP2; mutant; protein degradation; protein stability; retinal degeneration; structural model; transcription activator-like effector nuclease (TALEN); zebrafish