Cytoskeleton participation in subcellular trafficking of signal transduction proteins in rod photoreceptor cells

2002 ◽  
Vol 67 (3) ◽  
pp. 290-297 ◽  
Author(s):  
James F. McGinnis ◽  
Brian Matsumoto ◽  
James P. Whelan ◽  
Wei Cao
2007 ◽  
Vol 130 (1) ◽  
pp. 21-40 ◽  
Author(s):  
Keisuke Sakurai ◽  
Akishi Onishi ◽  
Hiroo Imai ◽  
Osamu Chisaka ◽  
Yoshiki Ueda ◽  
...  

Rod and cone photoreceptor cells that are responsible for scotopic and photopic vision, respectively, exhibit photoresponses different from each other and contain similar phototransduction proteins with distinctive molecular properties. To investigate the contribution of the different molecular properties of visual pigments to the responses of the photoreceptor cells, we have generated knock-in mice in which rod visual pigment (rhodopsin) was replaced with mouse green-sensitive cone visual pigment (mouse green). The mouse green was successfully transported to the rod outer segments, though the expression of mouse green in homozygous retina was ∼11% of rhodopsin in wild-type retina. Single-cell recordings of wild-type and homozygous rods suggested that the flash sensitivity and the single-photon responses from mouse green were three to fourfold lower than those from rhodopsin after correction for the differences in cell volume and levels of several signal transduction proteins. Subsequent measurements using heterozygous rods expressing both mouse green and rhodopsin E122Q mutant, where these pigments in the same rod cells can be selectively irradiated due to their distinctive absorption maxima, clearly showed that the photoresponse of mouse green was threefold lower than that of rhodopsin. Noise analysis indicated that the rate of thermal activations of mouse green was 1.7 × 10−7 s−1, about 860-fold higher than that of rhodopsin. The increase in thermal activation of mouse green relative to that of rhodopsin results in only 4% reduction of rod photosensitivity for bright lights, but would instead be expected to severely affect the visual threshold under dim-light conditions. Therefore, the abilities of rhodopsin to generate a large single photon response and to retain high thermal stability in darkness are factors that have been necessary for the evolution of scotopic vision.


Author(s):  
Anju D. ◽  
Pushpa Raj Poudel ◽  
Ajoy Viswam ◽  
Ashwini M. J.

Retinitis pigmentosa (RP) is an inherited, degenerative eye disease that causes severe vision impairment due to the progressive degeneration of rod photoreceptor cells in retina. This form of retinal dystrophy manifests initial symptoms independentof age; thus, RP diagnosis occurs anywhere from early infancy to late adulthood. This primary pigmentary retinal dystrophy is a hereditary disorder predominantly affecting the rods more than the cones. The main classical triads of retinitis pigmentosa are arteriolar attenuation, Retinal bone spicule pigmentation and Waxy disc pallor. The main treatment of retinitis pigmentosa is by using Low vision aids (LVA) and Genetic counseling. As such a complete cure for retinitis pigmentosa is not present. So a treatment protocol has to be adopted that helps in at least the symptomatic relief. In Ayurveda, the signs and symptoms of this can be compared with the Lakshanas of Doshandha which is one among the Dristigata Roga. It is considered as a diseased condition in which sunset will obliterate the Dristi Mandala and makes the person blind at night time. During morning hours the rising sunrays will disperse the accumulated Dosas from Dristi to clear vision. This disease resembles Kaphajatimira in its pathogenesis, but the night blindness is the special feature. Since the disease is purely Kaphaja, a treatment attempt is planned in Kaphara and Brimhana line. The present paper discusses a case of retinitis pigmentosa and it’s Ayurvedic Treatment.


2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Xiuqin Zhong ◽  
Max Lundberg ◽  
Lars Råberg

Abstract Differences in immune function between species could be a result of interspecific divergence in coding sequence and/or expression of immune genes. Here, we investigate how the degree of divergence in coding sequence and expression differs between functional categories of immune genes, and if differences between categories occur independently of other factors (expression level, pleiotropy). To this end, we compared spleen transcriptomes of wild-caught yellow-necked mice and bank voles. Immune genes expressed in the spleen were divided into four categories depending on the function of the encoded protein: pattern recognition receptors (PRR); signal transduction proteins; transcription factors; and cyto- and chemokines and their receptors. Genes encoding PRR and cyto-/chemokines had higher sequence divergence than genes encoding signal transduction proteins and transcription factors, even when controlling for potentially confounding factors. Genes encoding PRR also had higher expression divergence than genes encoding signal transduction proteins and transcription factors. There was a positive correlation between expression divergence and coding sequence divergence, in particular for PRR genes. We propose that this is a result of that divergence in PRR coding sequence leads to divergence in PRR expression through positive feedback of PRR ligand binding on PRR expression. When controlling for sequence divergence, expression divergence of PRR genes did not differ from other categories. Taken together, the results indicate that coding sequence divergence of PRR genes is a major cause of differences in immune function between species.


2012 ◽  
Vol 102 (3) ◽  
pp. 31a
Author(s):  
Peter Lanzerstorfer ◽  
Stefan Sunzenauer ◽  
Mario Brameshuber ◽  
Gerhard J. Schütz ◽  
Shin-Ichiro Takahashi ◽  
...  

2013 ◽  
Vol 53 (supplement1-2) ◽  
pp. S171
Author(s):  
Asuka Sakai ◽  
Hitomi Fujiwara ◽  
Masaya Fujita ◽  
Kazue Kurihara

2021 ◽  
Vol 67 (1) ◽  
pp. 20-28
Author(s):  
Alexandr Chernov ◽  
Irina Baldueva ◽  
Tatyana Nekhaeva ◽  
Elvira Galimova ◽  
Diana Alaverdian ◽  
...  

In review discusses the phenomenon of drug resistance of GB in the context of the expression of ABC family transporter proteins and the processes of proliferation, angiogenesis, recurrence and death. The emphasis is on the identifying for molecular targets among growth factors, receptors, signal transduction proteins, microRNAs, transcription factors, proto-oncogenes, tumor suppressor genes and their polymorphic variants (SNPs) for the development and creation of targeted anticancer drugs.


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