A5073359631- Connexins and lens biology
- Neuroscience and Neuropharmacology Research
- Nicotinic Acetylcholine Receptors Study
- Advanced Chemical Physics Studies
- Luminescence Properties of Advanced Materials
- Solid-state spectroscopy and crystallography
- Magnetism in coordination complexes
- Sphingolipid Metabolism and Signaling
- Photochemistry and Electron Transfer Studies
- Ion channel regulation and function
- Organic and Molecular Conductors Research
- Molecular Junctions and Nanostructures
- Heat shock proteins research
- Metal complexes synthesis and properties
- RNA Interference and Gene Delivery
- Retinal Development and Disorders
- Biochemical effects in animals
- Cardiac electrophysiology and arrhythmias
- RNA regulation and disease
- Lanthanide and Transition Metal Complexes
- Lysosomal Storage Disorders Research
- Lipid metabolism and biosynthesis
- Spectroscopy and Quantum Chemical Studies
- CRISPR and Genetic Engineering
- RNA Research and Splicing
University of Bonn
2008-2019
Life Science Institute
2013
Howard Hughes Medical Institute
2004
University Medical Center Utrecht
2004
Heinrich Heine University Düsseldorf
1982-1998
Rikkyo University
1987
(Dihydro)ceramide synthase 2 (cers2, formerly called lass2) is the most abundantly expressed member of ceramide gene family, which includes six isoforms in mice. CERS2 activity has been reported to be specific toward very long fatty acid residues (C22–C24). In order study biological role CERS2, we have inactivated its coding region transgenic mice using gene-trapped embryonic stem cells that express lacZ reporter DNA under control cers2 promoter. The resulting lack C24:1 brain as well liver...
Background— Connexin 43 (Cx43) is a major determinant of conduction in the ventricular working myocardium mammals. We investigated effect decreased Cx43 expression on velocity and arrhythmogenesis using adult mice with inducible deletion Cx43. Methods Results— Cre-ER(T)/+ mice, which 1 coding region gene was replaced by Cre-ER(T), were mated to fl/fl generating Cre-ER(T)/fl mice. Application 4-hydroxytamoxifen (4-OHT) induced Cre-ER(T)–mediated floxed allele. Epicardial mapping 13×19...
In the mammalian retina, rods feed into cone pathway through electrotonic coupling, and recent histological data suggest involvement of connexin36 (Cx36) in this pathway. We therefore generated Cx36 null mice monitored functional consequences deficiency on early visual transmission. The homozygous mutant had a normally developed retina showed no changes cellular organization rod contrast, coupling between AII amacrine cells bipolar was impaired. Recordings electroretinograms revealed...
To further characterize the recently described gap junction gene connexin 47 (Cx47), we generated Cx47-null mice by replacing Cx47 coding DNA with an enhanced green fluorescent protein (EGFP) reporter gene, which was thus placed under control of endogenous promoter. Homozygous mutant were fertile and showed no obvious morphological or behavioral abnormalities. Colocalization EGFP fluorescence immunofluorescence cell marker proteins revealed that mainly expressed in oligodendrocytes highly...
A new gap junction gene isolated from rat brain cDNA, mouse retina cDNA and genomic DNA is called connexin36, since it codes for a connexin protein of 321 amino acids corresponding to the theoretical molecular mass 36045 kDa (rat) 36084 (mouse). Only one acid residue differs between connexin36. In single murine connexin36 gene, an 1.14-kb intron interrupts coding region, similar as in homologous skate connexin35 gene. Because this unique feature, other 13 genes suggested form delta subclass...
Oculodentodigital dysplasia (ODDD) is a dominant negatively inherited disorder with variable but characteristic anomalies of the fingers and toes, eyes, face teeth, which are caused by mutations in connexin 43 (Cx43) gene. All analyzed so far have negative influence on conductance through gap junctional channels hemichannels, as well trafficking Cx43 protein transfected cells. In this study, we inserted human Cx43G138R point mutation into mouse gene generated mice conditionally expressing...
The thalamus plays important roles as a relay station for sensory information in the central nervous system (CNS). Although thalamic glial cells participate this activity, little is known about their properties. In study, we characterized formation of coupled networks between astrocytes and oligodendrocytes murine ventrobasal compared these properties with those hippocampus cortex. Biocytin filling individual or revealed large panglial all 3 gray matter regions. Combined analyses mice cell...
Ceramides are bioactive sphingolipids, which composed of sphingoid bases carrying acyl chains various lengths. synthesized by a family six ceramide synthases (CerS) in mammals, produce ceramides with different N-linked chains. Increased levels known to contribute the development obesity and insulin resistance. Recently, it has been demonstrated that acylation pattern is particular importance for an organism maintain energy homeostasis. However, CerS members involved this process not yet...
Connexin45 (Cx45) is known to be expressed in the retina, but its functional analysis was problematic because general deletion of Cx45 coding DNA resulted cardiovascular defects and embryonic lethality at day 10.5. We generated mice with neuron-directed concomitant activation enhanced green fluorescent protein (EGFP). EGFP labeling observed bipolar, amacrine, ganglion cell populations. Intracellular microinjection dyes EGFP-labeled somata combined immunohistological markers revealed...
A new mouse gap junction gene that codes for a protein of 46,551 Da has been identified and designated connexin47 (Cx47). It mapped as single-copy to chromosome 11. In human HeLa cells Xenopus oocytes, expression Cx47 or fusion enhanced green fluorescent induced intercellular channels displayed strong sensitivity transjunctional voltage. Tracer injections in Cx47-transfected revealed diffusion neurobiotin, Lucifer yellow, 4',6-diamidino-2-phenylindole. Recordings single yielded unitary...
Transgenic technology, immunocytochemistry, electrophysiology, intracellular injection techniques, and reverse transcription PCR were combined to study the expression of neuronal connexin36 (Cx36) in outer plexiform layer mouse retina. animals expressed either a fusion protein full-length Cx36 with enhanced green fluorescent (EGFP) attached at C terminus or exon 2 was replaced bybeta-galactosidase (beta-gal). In nuclear layer,beta-gal-positive cell bodies, which confined most distal region...
Targeted deletion of the connexin36 (Cx36) gene in mouse genome leads to visual transmission defects, weakened synchrony rhythmic inhibitory potentials neocortex, and disruption gamma-frequency network oscillations. We have generated transgenic mice which a reporter protein consisting exon1 coded N-terminal part Cx36 fused beta-galactosidase (N36-beta-gal) is expressed instead Cx36. Here, we used these for detailed analysis expression. By beta-gal staining adult retina, found expression lacZ...
In the mammalian heart, gap junction channels between electrically coupled cardiomyocytes are necessary for impulse propagation and coordinated contraction of atria ventricles. Recently, mouse connexin30.2 (Cx30.2) was shown to be expressed in cardiac conduction system, predominantly sinoatrial atrioventricular (AV) nodes. The corresponding junctional HeLa cells exhibit lowest unitary conductance (9 pS) all connexin channels. Here we report that Cx30.2 slows down excitation through AV node....
Five ceramide synthases (CerS2–CerS6) are expressed in mouse skin. Although CerS3 has been shown to fulfill an essential function during skin development, neither CerS6- nor CerS2-deficient mice show obvious phenotype. In order study the role of CerS4, we generated CerS4-deficient (Cers4−/−) and CerS4-specific antibodies. With these biological tools analysed tissue distribution determined cell-type specific expression CerS4 suprabasal epidermal layers footpads as well sebaceous glands dorsal...
Alpha-ganglion cells are present in all vertebrate retinae and subdivided into ON OFF types according to their level of dendritic ramification within the inner plexiform layer. They have large fields usually a good responsiveness moving stimuli. were first ganglion which tracer coupling was observed, suggesting presence gap junctions composed unknown connexins. Here we show that ON-alpha-ganglion mouse retina coupled amacrine cells, whereas OFF-alpha-ganglion other cells. These patterns...
Gap junction channels are intercellular conduits that allow diffusional exchange of ions, second messengers, and metabolites. Human oligodendrocytes express the gap protein connexin47 (Cx47), which is encoded by GJC2 gene. The autosomal recessive mutation hCx47M283T causes Pelizaeus-Merzbacher–like disease 1 (PMLD1), a progressive leukodystrophy characterized hypomyelination, retarded motor development, nystagmus, spasticity. We introduced human missense into orthologous position mouse Gjc2...