A5057357802- Retinal Development and Disorders
- Photoreceptor and optogenetics research
- Neuroscience and Neuropharmacology Research
- Receptor Mechanisms and Signaling
- Neurobiology and Insect Physiology Research
- Retinal Diseases and Treatments
- Cellular transport and secretion
- Lipid Membrane Structure and Behavior
- bioluminescence and chemiluminescence research
- Electromagnetic Fields and Biological Effects
- Nitric Oxide and Endothelin Effects
- Photochromic and Fluorescence Chemistry
- Mass Spectrometry Techniques and Applications
- Circadian rhythm and melatonin
- Zebrafish Biomedical Research Applications
- Ion-surface interactions and analysis
- Glycosylation and Glycoproteins Research
- Force Microscopy Techniques and Applications
- Photosynthetic Processes and Mechanisms
- Ion channel regulation and function
- Molecular Sensors and Ion Detection
- Phosphodiesterase function and regulation
- Analytical Chemistry and Sensors
- Advanced Fluorescence Microscopy Techniques
- Glaucoma and retinal disorders
Carl von Ossietzky Universität Oldenburg
2016-2025
University of Rostock
2024
University Medical Center
2024
Corning (United States)
2013-2022
Cornell University
2008
Lomonosov Moscow State University
2006
Forschungszentrum Jülich
1996-2005
Institut für Informationsverarbeitung
2002-2004
University of Pennsylvania
2003
Stanford University
1988-1990
Cyclic GMP causes the release of endogenous Ca2+ from rod outer segments, whose plasma membrane has been made permeable, or isolated discs.Approximately 11,000 ions are released per disc at saturating concentrations cyclic GMP.The velocity and amplitude dependent on concentration maximal rate efflux is -7 X lo4 s-l rod-'.The by independent light.The activation occurred within a narrow range (30-80 MM) does not obey simple Michaelis-Menten scheme.Instead, kinetic analysis Ca" suggests that...
Photoreceptor guanylate cyclase was solubilized and purified from bovine rod outer segments with 50-150-fold increase in specific activity using the nonionic detergent n-dodecyl-beta-D-maltoside. Guanylate activities correlated enrichment of a protein an apparent Mr = 112,000. The enzyme showed 100-700 nmol cGMP produced/min/mg exhibited positive cooperativity respect to MnGTP (Hill coefficient n 1.6 +/- 0.1). Km 274 67 microM, turnover number determined be 0.2-1.3 produced/s. molar ratio...
The membrane-bound guanylyl cyclase in vertebrate photoreceptor cells is one of the key enzymes visual transduction. It highly sensitive to free calcium concentration ([Ca2+]). activation process cooperative and mediated by a novel calcium-binding protein named GCAP (guanylyl cyclase-activating protein). We isolated from bovine rod outer segments, determined amino acid sequences proteolytically obtained peptides, cloned its gene. Ca2+-bound form native has an apparent molecular mass 20.5 kDa...
Abstract Migratory birds can sense the Earth’s magnetic field and use it for orientation over thousands of kilometres. A light-dependent radical-pair mechanism associated with visual system is currently discussed as underlying compass sense. The blue light receptor cryptochrome 4 (Cry4) considered most likely primary sensory protein that detects geomagnetic field. Since interaction partners Cry4 are completely unknown at present, here, we aim to identify potential candidate in avian retina....
In rod phototransduction, cyclic GMP synthesis by membrane bound guanylate cyclase ROS‐GC1 is under Ca 2+ ‐dependent negative feedback control mediated cyclase‐activating proteins, GCAP‐1 and GCAP‐2. The cellular concentration of GCAP‐2 approximately sums to the a functional dimer. Both GCAPs increase catalytic efficiency ( k cat / K m ) ROS‐GC1. However, presence myristoyl group in has strong impact on regulation ROS‐GC1, this contrast Catalytic increases 25‐fold when it reconstituted with...
The protein(s) that constitute(s) the cGMP-regulated channel in vertebrate photoreceptors has been solubilized from rod outer segment membranes and reincorporated into membrane of calcium-containing liposomes. properties reconstituted protein were determined by studying cGMP-stimulated efflux Ca2+ these Among several detergents tested zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) proved to be most suitable. Solubilization activity was found optimal...
The GUCA1A gene encodes the guanylate cyclase activating protein 1 (GCAP1) of mammalian rod and cone photoreceptor cells, which is involved in Ca2+-dependent negative feedback regulation membrane bound cyclases retina. Mutations have been associated with different forms dystrophies leading to impaired vision retinal degeneration. Here we report identification three novel one previously detected mutations: c.265G>A (p.Glu89Lys), c.300T>A (p.Asp100Glu), c.476G>T (p.Gly159Val) c.451C>T...
Abstract Background VISTA is a well-known immune checkpoint in T cell biology, but its role innate immunity less established. Here, we investigated the of on anticancer macrophage immunity, with focus phagocytosis, polarization and concomitant activation. Methods Macrophages, differentiated from overexpressed THP-1 cells cord blood CD34 + cell-derived monocytes, were used phagocytosis assay using B lymphoma target opsonized Rituximab. PBMC-derived macrophages to assess correlation between...
Since the middle of 20th century, long-distance avian migration has been known to rely partly on geomagnetic field. However, underlying sensory mechanism is still not fully understood. Cryptochrome-4a (ErCry4a), found in European robin (Erithacus rubecula), a night-migratory songbird, suggested be magnetic molecule. It sensitive external fields via so-called radical-pair mechanism. ErCry4a primarily located outer segments double-cone photoreceptor cells eye, which contain stacked and highly...
Introduction Genetic manipulation of murine retinal tissue through ocular administration adeno-associated viruses (AAVs) has become a standard technique to investigate multitude mechanisms underlying physiology. Resultantly, developments recombinant viral vectors with improved transduction efficiency and further methodological improvements have mostly focused on tissue, whereas AAVs successfully targeting avian retinae remained scarce. Methodology Using custom-designed injection setup, we...
In visual transduction, guanylate cyclase-activating proteins (GCAPs) activate the membrane-bound cyclase 1 (ROS-GC1) to synthesize cGMP under conditions of low cytoplasmic [Ca2+]free. GCAPs are neuronal Ca2+-binding with three functional EF-hands and a consensus site for N-terminal myristoylation. GCAP-1 GCAP-2 regulated ROS-GC1 activities differently. The myristoyl group in had strong influence on Ca2+-dependent regulation (shift IC50). contrast, myristoylation did not change activation...
The stereochemical course of the reaction catalyzed by guanylate cyclase from bovine retinal rod outer segments was investigated using phosphorothioate analogs GTP as chiral probes. (Sp)-Guanosine 5'-O-(1-thiotriphosphate) (Sp-GTP alpha S) is a substrate, whereas (Rp)-GTP S competitive inhibitor (K1 = 0.1 mM), but not substrate. (Sp)-GTP converted into (Rp)-guanosine 3':5'-monophosphorothioate, showing that proceeds with inversion configuration at alpha-phosphorus atom. Km and Vmax for (at...