Search results for "photor"
showing 10 items of 340 documents
A novel Usher protein network at the periciliary reloading point between molecular transport machineries in vertebrate photoreceptor cells.
2008
Contains fulltext : 69178.pdf (Publisher’s version ) (Closed access) The human Usher syndrome (USH) is the most frequent cause of combined deaf-blindness. USH is genetically heterogeneous with at least 12 chromosomal loci assigned to three clinical types, USH1-3. Although these USH types exhibit similar phenotypes in human, the corresponding gene products belong to very different protein classes and families. The scaffold protein harmonin (USH1C) was shown to integrate all identified USH1 and USH2 molecules into protein networks. Here, we analyzed a protein network organized in the absence of harmonin by the scaffold proteins SANS (USH1G) and whirlin (USH2D). Immunoelectron microscopic anal…
Gene-based treatment options for Usher type 1C by translational read-through of a nonsense mutation
2012
The Usher syndrome (USH) is the most frequent cause of inherited combined deaf-blindness. The ciliopathy is clinically and genetically heterogeneous, assigned to three clinical USH types of which the most severe type is USH1. The USH1C gene encodes the PDZ containing scaffold protein harmonin which is expressed in form of numerous alternatively spliced variants. Hamonin binds directly to all USH1/2 proteins and is a key organizer of USH protein networks in photoreceptor cells. So far no effective treatment for the ophthalmic component of USH exists. Translational read-through was introduced as an innovative therapy option for several non-ocular diseases caused by nonsense mutations leading …
Phosphorylation of the Usher syndrome 1G protein SANS controls Magi2-mediated endocytosis.
2014
Item does not contain fulltext The human Usher syndrome (USH) is a complex ciliopathy with at least 12 chromosomal loci assigned to three clinical subtypes, USH1-3. The heterogeneous USH proteins are organized into protein networks. Here, we identified Magi2 (membrane-associated guanylate kinase inverted-2) as a new component of the USH protein interactome, binding to the multifunctional scaffold protein SANS (USH1G). We showed that the SANS-Magi2 complex assembly is regulated by the phosphorylation of an internal PDZ-binding motif in the sterile alpha motif domain of SANS by the protein kinase CK2. We affirmed Magi2's role in receptor-mediated, clathrin-dependent endocytosis and showed tha…
Direct binding of Magi2 to the USH1G protein SANS links the periciliary USH protein network to endocytosis
2012
The human Usher syndrome (USH) is the most common form of combined deaf-blindness. The encoded molecules are integrated into protein networks by scaffolds including the USH1G protein SANS (scaffold protein containing ankyrin repeats and SAM domain). Previous studies indicated SANS´ participation in vesicle transport and cargo handover at the periciliary region of photoreceptor cells. To decipher the precise cellular role of SANS, we searched for interacting partners. Therefore we adopted a yeast-2-hybrid screen of a retinal cDNA library using SANS´ C-terminus as bait. Amongst others we identified the MAGUK protein Magi2 (membrane-associated guanylate kinase inverted-2) as putative binding p…
Evidence for synergistic and complementary roles of Bassoon and darkness in organizing the ribbon synapse
2012
Abstract Ribbon synapses are tonically active high-throughput synapses. The performance of the ribbon synapse is accomplished by a specialization of the cytomatrix at the active zone (CAZ) referred to as the synaptic ribbon (SR). Progress in our understanding of the structure–function relationship at the ribbon synapse has come from observations that, in photoreceptors lacking a full-size scaffolding protein Bassoon ( Bsn Δ Ex 4 / 5 ), dissociation of SRs coincides with perturbed signal transfer. The aim of the present study has been to elaborate the role of Bassoon as a structural organizer of the ribbon synapse and to differentiate it with regard to the ambient lighting conditions. The ul…
Direct interaction of the Usher syndrome 1G protein SANS and myomegalin in the retina
2011
Contains fulltext : 96822.pdf (Publisher’s version ) (Closed access) The human Usher syndrome (USH) is the most frequent cause of combined hereditary deaf-blindness. USH is genetically heterogeneous with at least 11 chromosomal loci assigned to 3 clinical types, USH1-3. We have previously demonstrated that all USH1 and 2 proteins in the eye and the inner ear are organized into protein networks by scaffold proteins. This has contributed essentially to our current understanding of the function of USH proteins and explains why defects in proteins of different families cause very similar phenotypes. We have previously shown that the USH1G protein SANS (scaffold protein containing ankyrin repeat…
Merging Visible-Light-Photoredox and Nickel Catalysis
2015
A new combination: The merging of visible‐light‐photoredox catalysis and nickel catalysis has been successfully achieved for cross‐coupling reactions. The synthetic scope and limitations of the combination of nickel and photoredox catalysis for Csp3-Csp2 cross‐coupling reactions is discussed.
Nxnl2 splicing results in dual functions in neuronal cell survival and maintenance of cell integrity
2012
International audience; The rod-derived cone viability factors, RdCVF and RdCVF2, have potential therapeutical interests for the treatment of inherited photoreceptor degenerations. In the mouse lacking Nxnl2, the gene encoding RdCVF2, the progressive decline of the visual performance of the cones in parallel with their degeneration, arises due to the loss of trophic support from RdCVF2. In contrary, the progressive loss of rod visual function of the Nxnl2-/- mouse results from a decrease in outer segment length, mediated by a cell autonomous mechanism involving the putative thioredoxin protein RdCVF2L, the second spliced product of the Nxnl2 gene. This novel signaling mechanism extends to o…
Polyamines and ripening of photoreceptor outer-segment in chicken embryo.
1995
Polyamines and their related monoacetyl derivatives were studied in rod outer segment (ROS) and cone outer segment (COS) of photoreceptor cells from chick embryo retina during eye development (7th-18th days). Putrescine was found to be necessary, in the second phase of retinogenesis, to sustain both ROS and COS differentiation and, after acetylation, gamma-aminobutyric acid synthesis. On the Other hand, spermidine and even more spermine intervene in the third phase of development when photoreceptors mature. Moreover, the presence of Nl-acetylspermidine already at the 7th day indicates that in the outer segment of photoreceptor cells too, as in the whole retina, putrescine synthesis comes ab…
Two-Dimensional Modeling of an Externally Irradiated Slurry Photoreactor
2013
Abstract A batch cylindrical photocatalytic reactor, externally irradiated by 1–6 UV fluorescent lamps and containing a stirred slurry of polycrystalline TiO2, was modeled by coupling a modified Langmuir–Hinshelwood kinetics together with a two-dimensional light intensity field. The radiation field has been determined on the main assumptions of diffuse radiation, isotropic scattering and negligible backward reflected photon flow. The model has been applied to the photocatalytic oxidation of organic substrates which do not undergo homogeneous photochemical degradation. The model is characterized by the following four parameters: the kinetic constants of substrate adsorption, desorption and d…