The protein phosphorylation pattern in the intact bovine retina has been investigated by labelling with 32P-phosphate under incubation conditions that preserve the electrical photoresponse of the photoreceptor cells. The phosphorylation of rod outer segment proteins was analysed after isolation of outer segments from the labelled retina. The global influence of light, Ca2+ and the phosphodiesterase inhibitor, isobutylmethylxanthine, on protein phosphorylation in rod outer segments was analysed. A 12 kDa protein is the most prominent phosphorylated species in the intact bovine retina. Its phosphorylation is increased by light and/or Ca2+. Evidence is presented that this strongly phosphorylated protein is not located in the outer segment, and we suggest that it may be a synaptic protein. Retinal rod outer segment membrane proteins with apparent molecular weights of 245, 226, 125, 110, 50, 46, 38 and 20 all show light-stimulated phosphorylation. Lowering the extracellular Ca2+ levels results in a decrease of the phosphorylation level of some of these proteins, viz. at 125, 50, 38 and probably at 20 kDa. Such proteins, whose phosphorylation level is influenced both by light and by elevated Ca2+, are candidates for mediators of phototransduction. The phosphorylated species at 245, 226, 110, 50 and 20 kDa are enriched in rod outer segment plasma membrane preparations. These protein species could participate in the light-regulated modulation of the Na+-conductance of the plasma membrane.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0304-4165(86)90004-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Hardy-Rand-Rittler colour vision testing in cone and cone-rod dystrophies: correlation with structural and functional outcome measures.
Eye (Lond)
January 2025
Save Sight Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.
Purpose: To determine how Hardy-Rand-Rittler (HRR) colour vision testing correlates with visual functional and structural assessments in Cone and Cone-Rod Dystrophy.
Methods: Thirty-four Cone and 69 Cone-Rod Dystrophy patients diagnosed by electroretinography (ERG) at the Save Sight Institute in Sydney were included in a retrospective analysis. Each patient's HRR colour vision test scores were compared with markers of cone and rod system function including visual acuity (VA), ERG responses, changes on Spectral Domain Optical Coherence Tomography (OCT) and Fundus Autofluorescence.
Unique ultrastructural organization of human rod photoreceptors.
Commun Biol
January 2025
Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA.
Rod and cone photoreceptor cells are specialized neurons responsible for transforming the information reaching the eyes in the form of photons into the language of neuronal activity. Rods are the most prevalent photoreceptor type, primarily responsible for light detection under conditions of limited illumination. Here we demonstrate that human rods have a morphological organization unique among all described species, whereby the cell soma extends alongside the light-sensitive outer segment compartment to form a structure we have termed the "accessory inner segment.
View Article and Find Full Text PDFLongitudinal assessment of retinal and visual pathway electrophysiology and structure after high altitude exposure.
Graefes Arch Clin Exp Ophthalmol
January 2025
Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China.
High altitude (HA) exposure induces impairments in visual function. This study was designed to dynamically observe visual function after returning to lowland and elucidate the underlying mechanism by examining the structure and function of retina and visual pathway. Twenty-three subjects were recruited before (Test 1), and one week (Test 2) and three months (Test 3) after their return from HA (4300 m) where they resided for 30 days.
View Article and Find Full Text PDFRabin8 phosphorylated by NDR2/STK38L, the canine early retinal degeneration (erd) gene product, directs rhodopsin Golgi-to-cilia trafficking.
J Cell Sci
January 2025
Department of Ophthalmology and Visual Sciences, University of New Mexico, Albuquerque, New Mexico 87131, Mexico.
The Rab11-Rabin8-Rab8 ciliogenesis complex regulates the expansion of cilia-derived light-sensing organelles, the rod outer segments, via post-Golgi rhodopsin transport carriers (RTCs). Rabin8, an effector of Rab11 and a nucleotide exchange factor (GEF) for Rab8, is phosphorylated at S272 by NDR2 kinase (aka STK38L), a canine erd gene product linked to the human ciliopathy Leber congenital amaurosis (LCA). Here, we define the step at which NDR2 phosphorylated Rabin8 regulates Rab11-Rab8 succession in X.
View Article and Find Full Text PDFCanine Best disease as a translational model.
Eye (Lond)
January 2025
Division of Experimental Retinal Therapies, Department of Clinical Sciences, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA.
In this review, we summarize the findings of several pre-clinical studies in the canine BEST1 disease model. To this end, client-owned and purpose bred dogs that were compound heterozygotes or homozygotes, respectively, for two or one of 3 different mutations in BEST1 were evaluated by ophthalmic examination, cSLO/sdOCT imaging, and retinal immunohistochemistry to characterize the clinical and microanatomic features of the disease. Subsequently AAV-mediated gene therapy was done to transfer the BEST1 transgene to the RPE under control of a hVMD2 promoter.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!