Eglof Ritter

Learn More
The construction of a restriction fragment length polymorphism (RFLP) linkage map is based on the estimation of recombination frequencies between genetic loci and on the determination of the linear order of loci in linkage groups. RFLP loci can be identified as segregations of singular or allelic DNA-restriction fragments. From crosses between heterozygous(More)
Phytophthora infestans is the most important fungal pathogen in the cultivated potato (Solanum tuberosum). Dominant, race-specific resistance alleles and quantitative resistance--the latter being more important for potato breeding--are found in the germplasm of cultivated and wild potato species. Quantitative trait loci (QTLs) for resistance to two races of(More)
Vertebrate rhodopsin consists of the apoprotein opsin and the chromophore 11-cis-retinal covalently linked via a protonated Schiff base. Upon photoisomerization of the chromophore to all-trans-retinal, the retinylidene linkage hydrolyzes, and all-trans-retinal dissociates from opsin. The pigment is eventually restored by recombining with enzymatically(More)
Channelrhodopsin-2 (ChR2) is a microbial type rhodopsin and a light-gated cation channel that controls phototaxis in Chlamydomonas. We expressed ChR2 in COS-cells, purified it, and subsequently investigated this unusual photoreceptor by flash photolysis and UV-visible and Fourier transform infrared difference spectroscopy. Several transient photoproducts of(More)
The guanine nucleotide-binding protein (G-protein)-coupled receptor superfamily (GPCR) is comprised of a large group of membrane proteins involved in a wide range of physiological signaling processes. The functional switch from a quiescent to an active conformation is at the heart of GPCR action. The GPCR rhodopsin has been studied extensively because of(More)
The ml-o locus in barley confers resistance to all known races of the fungus Erysiphe graminis f.sp. hordei. Since the molecular mechanisms underlying ml-o-mediated resistance are currently undefined, experiments have been initiated to isolate the gene by means of its map position. A collection of backcross lines containing ml-o alleles derived from six(More)
The light-activated microbial ion channel channelrhodopsin-2 (ChR2) is a powerful tool to study cellular processes with high spatiotemporal resolution in the emerging field of optogenetics. To customize the channel properties for optogenetic experiments, a detailed understanding of its molecular reaction mechanism is essential. Here, Glu-90, a key residue(More)
Absorption of light in rhodopsin leads through 11-cis- and all-trans-retinal isomerization, proton transfers, and structural changes to the active G-protein binding meta-II state. When meta-II is photolysed by blue light absorption, the activating pathway is apparently reverted, and rhodopsin is photoregenerated. However, the product formed, a P subspecies(More)
The visual process in rod cells is initiated by absorption of a photon in the rhodopsin retinal chromophore and consequent retinal cis/trans-isomerization. The ring structure of retinal is thought to be needed to transmit the photonic energy into conformational changes culminating in the active metarhodopsin II (Meta II) intermediate. Here, we demonstrate(More)
Channelrhodopsins are microbial type rhodopsins that operate as light-gated ion channels. Largely prolonged lifetimes of the conducting state of channelrhodopsin-2 may be achieved by mutations of crucial single amino acids, i.e. cysteine 128. Such mutants are of great scientific interest in the field of neurophysiology because they allow neurons to be(More)