Mitarbeiter // Katja Koeppen

Scientific interest

Functional characterization of mutant CNGA3 channels
Mutations in the CNGA3 gene have been associated with complete and incomplete forms of total colorblindness (achromatopsia), an autosomal-recessive inherited retinal disorder characterized by reduced visual acuity, lack of color discrimination, photophobia and nystagmus. CNGA3 encodes the A-subunit of the cone photoreceptor cyclic nucleotide-gated (CNG) channel. As the only source of calcium in cone outer segments this non-selective cation channel plays an essential role in the phototransduction cascade. The focus of the project is the heterologous expression and functional analysis of CNGA3 channels with mutations that have been found in patients with achromatopsia. Applied methods include in vitro mutagenesis, DNA-sequencing, cell culture and transfection, immunocytochemisty, calcium imaging and electrophysiology (patch-clamp technique).