D1: The regeneration-module in photoreceptor cells

In retinal rods the receptor rhodopsin and visual arrestin are at the interlink between three modular functions, namely, G protein coupled signaling, receptor regeneration and translocation of proteins. We want to study how the channeling of the retinal ligand during rhodopsin regeneration works. Main goals are the characterization of the retinal entrance and exit routes and the role of protein flexibility in retinal channeling. We also want to explore the interplay between retinal release and arrestin binding, in order to understand how arrestin protects the rod cell from toxic levels of all-trans-retinal

Selected Publications

Sommer, ME, Hofmann, KP and Heck, M
Not just signal shut-off: the protective role of arrestin-1 in rod cells.
Handb Exp Pharmacol 2014; 219:101-16.
Kim YJ, Hofmann KP, Ernst OP, Scheerer P, Choe HW, Sommer ME
Crystal structure of pre-activated arrestin p44.
Nature 2013; 497(7447):142-6.
Elgeti M, Rose AS, Bartl FJ, Hildebrand PW, Hofmann KP, Heck M
Precision vs Flexibility in GPCR signaling.
J Am Chem Soc 2013; 21(135):12305-12.
Park, JH, Morizumi, T, Li, Y, Hong, JE, Pai, EF, Hofmann, KP, Choe, HW and Ernst, OP
Opsin, a structural model for olfactory receptors?.
Angew Chem Int Ed Engl 2013; 52(42):11021-4.
Sommer M.E., Hofmann K.P., Heck M.
Distinct loops in arrestin differentially regulate ligand binding within the GPCR opsin.
Nature Communications 2012; 3:1273.
Piechnick, R., Ritter E., Hildebrand, P.W., Ernst, O.P., Scheerer, P., Hofmann, K.P., Heck, M.
Effect of channel mutations on the uptake and release of the retinal ligand in opsin.
Proc Natl Acad Sci USA 2012; 109(14):5247-5252.
Elgeti, M., Kazmin, R., Heck,M., Morizumi, T., Ritter, E., Scheerer, P., Ernst, O.P., Siebert, F., Hofmann, K.P., Bartl, F.J.
Conserved Tyr223(5.58) plays different roles in the activation and G-protein interaction of rhodopsin.
J Am Chem Soc 2011; 133(18):7159-65.
Choe, H. W., Kim, Y. J., Park, J. H., Morizumi, T., Pai, E. F., Krauß, N., Hofmann, K. P., Scheerer, P., Ernst, O. P.
Crystal structure of metarhodopsin II.
Nature 2011; 471(7340):651-5.
Sommer, M.E. Hofmann, K.P. & Heck, M.
Arrestin-rhodopsin binding stoichiometry in isolated rod outer segment membranes depends on the percentage of activated receptors.
J Biol Chem 2011; 286:7359-7369.
Piechnick, R., Heck, M., Sommer, M.E.
Alkylated hydroxylamine derivatives eliminate peripheral retinylidene Schiff bases but cannot enter the retinal binding pocket of light-activated rhodopsin.
Biochemistry 2011; 50(33):7168-76.