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Biology subjects

Arndt, H.-D.

Publications and source records attributed to Arndt, H.-D..

2 recordsLinked to original sources

Next Generation Opto-Jasplakinolides Enable Local Remodeling of Actin Networks

The natural product jasplakinolide is a widely used tool compound to stabilize F-actin and influence actin dynamics. We have previously introduced photoswitchable jasplakinolides (optojasps) that are activated with violet light and deactivated with blue light. Based on insights from cryo-electron microscopy and structure-activity relationship (SAR) studies, we now developed a new generation of functionally superior optojasps that are better suited for biological investigations. These compounds are procured through chemical total synthesis and feature rationally designed red-shifted azobenzene photoswitches. Our new optojasps can be activated with longer wavelengths in the visible range (e.g. 440-477 nm) and rapidly return to their inactive state through thermal relaxation. This has enabled the reversible control of F-actin dynamics, as shown through live-cell imaging and cell migration, as well as cell proliferation assays. Brief sub-cellular activation with blue-green light resulted in highly localized F-actin clusters that gradually dissolved in the dark. Our light-responsive tools can be useful in diverse fields to study actin dynamics with outstanding spatiotemporal precision. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=87 SRC="FIGDIR/small/480923v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1883e3corg.highwire.dtl.DTLVardef@1ae0c4borg.highwire.dtl.DTLVardef@1a92f8forg.highwire.dtl.DTLVardef@718d87_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

Orfamide-A-mediated bacterial-algal interactions involve specific Ca2+ signalling pathways

The antagonistic bacterium Pseudomonas protegens secretes the cyclic lipopeptide orfamide A, which triggers a Ca2+ signal, causing the deflagellation of the green microalga Chlamydomonas reinhardtii. By investigating targeted synthetic orfamide A variants and inhibitors, we found that at least two Ca2+-signalling pathways and TRP channels are involved in this response.

microbiology↗