Knockout of RP2 decreases GRK1 and rod transducin subunits and leads to photoreceptor degeneration in zebrafish

Fei Liu, Jiaxiang Chen, Shanshan Yu, Rakesh Kotapati Raghupathy, Xiliang Liu, Yayun Qin, Chang Li, Mi Huang, Shengjie Liao, Jiuxiang Wang, Jian Zou, Xinhua Shu, Zhaohui Tang*, Mugen Liu*

*Corresponding author for this work

Research output: Contribution to journalArticle

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.
Original languageEnglish
Pages (from-to)4648-4659
Number of pages12
JournalHuman Molecular Genetics
Volume24
Issue number16
Early online date1 Jun 2015
DOIs
Publication statusPublished - 15 Aug 2015

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Keywords

  • photoreceptors
  • transducin
  • zebrafish
  • retina
  • tissue degeneration

Cite this

Liu, F., Chen, J., Yu, S., Raghupathy, R. K., Liu, X., Qin, Y., Li, C., Huang, M., Liao, S., Wang, J., Zou, J., Shu, X., Tang, Z., & Liu, M. (2015). Knockout of RP2 decreases GRK1 and rod transducin subunits and leads to photoreceptor degeneration in zebrafish. Human Molecular Genetics, 24(16), 4648-4659. https://doi.org/10.1093/hmg/ddv197