SiR‐XActin: A Fluorescent Probe for Imaging Actin Dynamics in Live Cells

V Veselin Nasufovic J Julian Kompa (Department of Chemical Biology) H Halli L. Lindamood (Department of Neuroscience and Regenerative Medicine Medical College of Georgia at Augusta University 1120 15th Street Augusta Georgia 30912 USA) M Merle Blümke (Institut für Organische und Makromolekulare Chemie Friedrich‐Schiller‐Universität Humboldtstr. 10 D‐07743 Jena Germany) R Rayane Dibsy (Membrane, Cytoskeleton and Cell Division Unit CNRS UMR3691 Institut Pasteur Université Paris Cité 25–28 rue du Dr Roux Paris F‐75015 France) B Birgit Koch V Victoria Levario‐Diaz (Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany) K Katharina Weber (Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany) M Marlene Maager (Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany) E Ekaterina Nomerotskaia (Institut für Organische und Makromolekulare Chemie Friedrich‐Schiller‐Universität Humboldtstr. 10 D‐07743 Jena Germany) A Arnaud Echard E Elisabetta Ada Cavalcanti‐Adam (Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany) E Eric A. Vitriol H Hans‐Dieter Arndt (Institut für Organische und Makromolekulare Chemie Friedrich‐Schiller‐Universität Humboldtstr. 10 D‐07743 Jena Germany) K Kai Johnsson (Department of Chemical Biology)

Abstract

Abstract Imaging actin‐dependent processes in live cells is important for understanding numerous biological processes. However, currently used natural‐product‐based fluorescent probes for actin filaments affect the dynamics of actin polymerization and can induce undesired cellular phenotypes. Here, we introduce SiR‐XActin, a simplified jasplakinolide‐based, far‐red fluorescent probe that enables bright and photostable staining in various cell types without requiring genetic modifications. Due to its relatively weak binding affinity, the probe exhibits minimal cytotoxicity and labels actin filaments without significantly altering actin dynamics. Furthermore, SiR‐XActin is suitable for time‐resolved, live‐cell super‐resolution STED microscopy. Exchanging the SiR fluorophore in SiR‐XActin for other fluorophores yields probes in different colors. All these properties make SiR‐XActin and its analogs powerful tools for studying actin dynamics using live‐cell fluorescence microscopy.

Article Details

Volume / Issue Vol. 64, Issue 50
Published December 08, 2025
ISSN 1433-7851
Publisher Wiley

Journal Info

Angewandte Chemie International Edition

Wiley

ISSN: 1433-7851 Physical Sciences

Authors (15)

V

Veselin Nasufovic

J

Julian Kompa

Department of Chemical Biology

H

Halli L. Lindamood

Department of Neuroscience and Regenerative Medicine Medical College of Georgia at Augusta University 1120 15th Street Augusta Georgia 30912 USA

M

Merle Blümke

Institut für Organische und Makromolekulare Chemie Friedrich‐Schiller‐Universität Humboldtstr. 10 D‐07743 Jena Germany

R

Rayane Dibsy

Membrane, Cytoskeleton and Cell Division Unit CNRS UMR3691 Institut Pasteur Université Paris Cité 25–28 rue du Dr Roux Paris F‐75015 France

B

Birgit Koch

V

Victoria Levario‐Diaz

Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany

K

Katharina Weber

Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany

M

Marlene Maager

Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany

E

Ekaterina Nomerotskaia

Institut für Organische und Makromolekulare Chemie Friedrich‐Schiller‐Universität Humboldtstr. 10 D‐07743 Jena Germany

A

Arnaud Echard

E

Elisabetta Ada Cavalcanti‐Adam

Department of Cellular Biophysics Max Planck Institute for Medical Research Jahnstrasse 29 D‐69120 Heidelberg Germany

E

Eric A. Vitriol

H

Hans‐Dieter Arndt

Institut für Organische und Makromolekulare Chemie Friedrich‐Schiller‐Universität Humboldtstr. 10 D‐07743 Jena Germany

K

Kai Johnsson

Department of Chemical Biology