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BP: Fachverband Biologische Physik
BP 8: Cytoskeletal filaments
BP 8.10: Talk
Tuesday, April 2, 2019, 12:30–12:45, H10
Experimental Characterization and Theoretic Modeling of Circular Dorsal Ruffles — Julia Lange1, Malte Ohmstede1, •Merthe Schwachenwald1,2, Christof Taxis2, and Hans-Günther Döbereiner1 — 1Institut für Biophysik, Universität Bremen — 2Fachbereich Biologie, Phillips-Universität Marburg
Circular Dorsal Ruffles (CDRs) are dynamic actin structures propagating on the dorsal cell side. Three factors influence CDR dynamics: Stimulation with growth factors, protein composition, and boundary conditions of cells. In our set-up the latter is ensured by using micro-contact printed substrates to receive an even cell shape. The influence of different proteins and growth factor stimulation on CDR dynamics is controlled by microfluidics and examined with light microscopy. We will use optogenetics to control protein expression linking a light sensitive protein to a peptide degron and connect both to an actin regulator. This leads to a degradation of the construct, when exposing it to blue light. Optogenetic manipulation allows a more refined control of protein concentration than with traditional biochemical means. CDR dynamics under changing biochemical conditions is compared with theory through two-dimensional simulations of propagating wave fronts. We aim to verify a bistable model and augment it to include the effects of fluctuations in an active cytosol. We found CDR characteristics to cluster with their number. Moreover, we observe clear long-distance interaction of CDRs. We examine the effects of Jasplakinolide (Actin inhibitor), Wiskostatin (N-WASP inhibitor), and Wortmannin (PI3K inhibitor) on wave characteristics.