TitleStructural insights into actin filament recognition by commonly used cellular actin markers.
Publication TypeJournal Article
Year of Publication2020
AuthorsKumari A, Kesarwani S, Javoor MG, Vinothkumar KR, Sirajuddin M
JournalEMBO J
Date Published2020 Jul 15

Cellular studies of filamentous actin (F-actin) processes commonly utilize fluorescent versions of toxins, peptides, and proteins that bind actin. While the choice of these markers has been largely based on availability and ease, there is a severe dearth of structural data for an informed judgment in employing suitable F-actin markers for a particular requirement. Here, we describe the electron cryomicroscopy structures of phalloidin, lifeAct, and utrophin bound to F-actin, providing a comprehensive high-resolution structural comparison of widely used actin markers and their influence towards F-actin. Our results show that phalloidin binding does not induce specific conformational change and lifeAct specifically recognizes closed D-loop conformation, i.e., ADP-Pi or ADP states of F-actin. The structural models aided designing of minimal utrophin and a shorter lifeAct, which can be utilized as F-actin marker. Together, our study provides a structural perspective, where the binding sites of utrophin and lifeAct overlap with majority of actin-binding proteins and thus offering an invaluable resource for researchers in choosing appropriate actin markers and generating new marker variants.

Alternate JournalEMBO J.
PubMed ID32567727
PubMed Central IDPMC7360965
Grant ListSB/S2/RJN-094/2017 / / Science and Engineering Research Board (SERB) /
IA/I/14/2/501533 / / The Wellcome Trust DBT India Alliance (India Alliance) /
/ / European Molecular Biology Organization (EMBO) /
RA-40796915460 / / Department of Biotechnology, Ministry of Science and Technology (DBT) /
/ WT_ / Wellcome Trust / United Kingdom
/ / Central Imaging and Flow Facility (CIFF) /
DBT/PR12422/MED/31/287/2014 / / Department of Biotechnology, Ministry of Science and Technology (DBT) /
5703-1 / / Indo-French Centre for the Promotion of Advanced Research (IFCPAR) /