The Na+/Ca2+, K+ exchanger NCKX4 is required for efficient cone-mediated vision

eLife

Alicia De Maria¹  Haiqing Zhao²  Jeannie Chen³  Vladimir J Kefalov⁴  Frans Vinberg⁴  Steven Bassnett⁴  Tian Wang⁵ 

[1] Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, United States;Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, United States;Department of Biology, Johns Hopkins University, Baltimore, United States;Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, United States;Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States;

关键词: photoreceptors;    calcium;    light adaptation;    NCKX;    retinal degeneration;    color vision;   

DOI  :  10.7554/eLife.24550

来源: DOAJ

【 摘 要 】

Calcium (Ca2+) plays an important role in the function and health of neurons. In vertebrate cone photoreceptors, Ca2+ controls photoresponse sensitivity, kinetics, and light adaptation. Despite the critical role of Ca2+ in supporting the function and survival of cones, the mechanism for its extrusion from cone outer segments is not well understood. Here, we show that the Na+/Ca2+, K+ exchanger NCKX4 is expressed in zebrafish, mouse, and primate cones. Functional analysis of NCKX4-deficient mouse cones revealed that this exchanger is essential for the wide operating range and high temporal resolution of cone-mediated vision. We show that NCKX4 shapes the cone photoresponse together with the cone-specific NCKX2: NCKX4 acts early to limit response amplitude, while NCKX2 acts late to further accelerate response recovery. The regulation of Ca2+ by NCKX4 in cones is a novel mechanism that supports their ability to function as daytime photoreceptors and promotes their survival.

【 授权许可】

Unknown