Results

RDF/XMLNTriplesTurtleShow queryShare ▶
SubjectPredicateObject
http://purl.uniprot.org/citations/18952919http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/18952919http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/18952919http://www.w3.org/2000/01/rdf-schema#comment"

Purpose

Photoreceptor ribbon synapses translate light-dependent changes of membrane potential into graded transmitter release via L-type voltage-dependent calcium channel (VDCC) activity. Functional abnormalities (e.g., a reduced electroretinogram b-wave), arising from mutations of presynaptic proteins, such as Bassoon and the VDCCalpha1 subunit Cacna1f, have been shown to altered transmitter release. L-type VDCCalpha1 subtype expression in wild-type and mutant mice was examined, to investigate the underlying pathologic mechanism.

Methods

Two antisera against Cacna1f, and a Cacna1f mouse mutant (Cacna1fDeltaEx14-17) were generated. Immunocytochemistry for L-type VDCCalpha1 subunits and additional synaptic marker proteins was performed in wild-type, BassoonDeltaEx4-5 and Cacna1fDeltaEx14-17 mice.

Results

Active zone staining at photoreceptor ribbon synapses with a panalpha1 antibody colocalized with staining for Cacna1f in wild-type mouse retina. Similarly, in the BassoonDeltaEx4-5 mouse, residual mislocalized staining for panalpha1 and Cacna1f showed colocalization. Unlike the presynaptic location of Cacna1f and panalpha1 antibody staining, the skeletal muscle VDCCalpha1 subunit Cacna1s was present postsynaptically at ON-bipolar cell dendrites, where it colocalized with metabotropic glutamate receptor 6 (mGluR6). Surprisingly, Cacna1s labeling was severely downregulated in the BassoonDeltaEx4-5 and Cacna1fDeltaEx14-17 mutants. Subsequent analyses revealed severely reduced ON-bipolar cell dendritic expression of the sarcoplasmic reticulum Ca(2+) ATPase Serca2 in both mouse mutants and of mGluR6 in the Cacna1fDeltaEx14-17 mutant.

Conclusions

Presynaptic mutations leading to reduced photoreceptor-to-bipolar cell signaling are associated with disturbances in protein expression within postsynaptic dendrites. Moreover, detection of Cacna1s and Serca2 in ON-bipolar cell dendrites in wild-type animals suggests a putative role in regulation of postsynaptic Ca(2+) flux."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.org/dc/terms/identifier"doi:10.1167/iovs.08-2758"xsd:string
http://purl.uniprot.org/citations/18952919http://purl.org/dc/terms/identifier"doi:10.1167/iovs.08-2758"xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Brandstatter J.H."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Brandstatter J.H."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Koentgen F."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Koentgen F."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Wolfrum U."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Wolfrum U."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Turner P."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Turner P."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Maw M."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Maw M."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"tom Dieck S."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"tom Dieck S."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Dearden P."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Dearden P."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Specht D."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Specht D."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Wu S.B."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/author"Wu S.B."xsd:string
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/date"2009"xsd:gYear
http://purl.uniprot.org/citations/18952919http://purl.uniprot.org/core/date"2009"xsd:gYear
▶