Humboldt-Universität zu Berlin - Experimentelle Biophysik

Ulrike Scheib

In July 2013, I joined the Hegemann lab and in my PhD I focus on a recently discovered class of enzyme rhodopsins. In particular, I am interested in rhodopsin guanylyl cyclases (RhGC) which were first -and so far- solely discovered in aquatic fungi of the Blastocladiomycota phyla₁. The outstanding characteristic of these novel retinal based photoreceptors is the direct connection between the photosensory rhodopsin domain and a guanylyl cyclase, via a putative coiled coil linker of 40 amino acid length. By Two Electrode Voltage Clamp experiments in Xenopus oocytes and ELISA based quantifications I could show that illumination with green light activates RhGCs from Blastocladiella Emersonii (BeRhGC) to produce cGMP within milliseconds. cGMP is a crucial 2nd messenger for major cellular processes like vision, metabolism, smooth muscle relaxation₂. Together with our collaboration partners, we could show that BeRhGC can be applied in different mammalian cell types as new optogenetic tool to control cGMP synthesis and signaling with light₃. Currently, I am working on the detailed enzymatic characterization of RhGC to understand how the intramolecular signal is propagated from the light-sensing rhodopsin domain to the guanylyl cyclase.

1. Avelar GM, Schumacher RI, Zaini PA, Leonard G, Richards TA, Gomes SL. A rhodopsin-guanylyl cyclase gene fusion functions in visual perception in a fungus. Curr Biol. 2014;24(11):1234-1240. doi:10.1016/j.cub.2014.04.009.

2. Lucas KA, Pitari GM, Kazerounian S, et al. Guanylyl cyclases and signaling by cyclic GMP. Pharmacol Rev. 2000;52(3):375-414. http://www.ncbi.nlm.nih.gov/pubmed/10977868. Accessed April 10, 2017.

3. Scheib U, Stehfest K, Gee CE, et al. The rhodopsin-guanylyl cyclase of the aquatic fungus Blastocladiella emersonii enables fast optical control of cGMP signaling. Sci Signal. 2015;8(389):rs8. doi:10.1126/scisignal.aab0611.

Poster & talk awards

- 8th international Conference on cGMP, Bamberg 06/2017: Young researcher talk and poster award

- The International Chemical Congress of Pacific Basin Societies 2020, Hawaii 12/2015: Student poster competition award 

Publications:

Penzkofer A, Scheib U, Hegemann P, Stehfest K. Absorption and emission spectroscopic investigation of thermal dynamics and photo-dynamics of the rhodopsin domain of the rhodopsin-guanylyl cyclase from the aquatic fungus Blastocladiella emersonii. 2016. https://epub.uni-regensburg.de/35140/. Accessed August 17, 2017.

Scheib U, Stehfest K, Gee CE, et al. The rhodopsin-guanylyl cyclase of the aquatic fungus Blastocladiella emersonii enables fast optical control of cGMP signaling. Sci Signal. 2015;8(389):rs8. doi:10.1126/scisignal.aab0611.

http://www.oertner.com/PDF/Scheib2015.pdf

Richter F, Scheib US, Mehlhorn J, et al. Upgrading a microplate reader for photobiology and all-optical experiments. Photochem Photobiol Sci. 2015;14(2):270-279. doi:10.1039/C4PP00361F. 

Scheib U, Shanmugaratnam S, Farías-Rico JA, Höcker B. Change in protein-ligand specificity through binding pocket grafting. J Struct Biol. 2014;185(2):186-192. doi:10.1016/j.jsb.2013.06.002.

Urban JF, Hu Y, Miller MM, Scheib U, Yiu YY, Aroian R V. Bacillus thuringiensis-derived Cry5B Has Potent Anthelmintic Activity against Ascaris suum. Geary TG, ed. PLoS Negl Trop Dis. 2013;7(6):e2263. doi:10.1371/journal.pntd.0002263.

Hui F, Scheib U, Hu Y, Sommer RJ, Aroian R V., Ghosh P. Structure and Glycolipid Binding Properties of the Nematicidal Protein Cry5B. Biochemistry. 2012;51(49):9911-9921. doi:10.1021/bi301386q. ;