A Single Residue Mutation in the Gαq Subunit of the G Protein Complex Causes Blindness in Drosophila

G3: Genes, Genomes, Genetics

Jinguo Cao^1¹  Murali K. Bollepalli^2²  Yuhui Hu^1³  Jin Zhang^3⁴ 

[1] Department of Medicine, Jinggang Shan University, Ji’an 343009, China^1;Department of Physiology, Development and Neuroscience, University of Cambridge, CB2 3DY, United Kingdom^2;School of Basic Medical Sciences, Nanchang University, Jiangxi 330031, China^3;School of Life Sciences, Institute of Entomology, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou 510006, China^4

关键词: phototransduction;    photoreceptor;    G protein;    ERG;    Gαq;    Gα PLC interaction;    light-induced retinal degeneration;   

DOI  :  10.1534/g3.117.300340

学科分类：生物科学（综合）

来源: Genetics Society of America

【 摘 要 】

Heterotrimeric G proteins play central roles in many signaling pathways, including the phototransduction cascade in animals. However, the degree of involvement of the G protein subunit Gα_q is not clear since animals with previously reported strong loss-of-function mutations remain responsive to light stimuli. We recovered a new allele of Gα_q in Drosophila that abolishes light response in a conventional electroretinogram assay, and reduces sensitivity in whole-cell recordings of dissociated cells by at least five orders of magnitude. In addition, mutant eyes demonstrate a rapid rate of degeneration in the presence of light. Our new allele is likely the strongest hypomorph described to date. Interestingly, the mutant protein is produced in the eyes but carries a single amino acid change of a conserved hydrophobic residue that has been assigned to the interface of interaction between Gα_q and its downstream effector, PLC. Our study has thus uncovered possibly the first point mutation that specifically affects this interaction in vivo .

【 授权许可】

CC BY