Department of Biotechnology
inStem (Institute for Stem Cell Science and Regenerative Medicine)

Structural insights into actin filament recognition by commonly used cellular actin markers.

Publication Type

Journal Article

Date of Publication

July 15, 2020

Journal

The EMBO journal

Volume/Issue

39/14

ISSN

1460-2075

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 Journal

EMBO J

PubMed ID

32567727

PubMed Central ID

PMC7360965

Authors

Archana Kumari
Shubham Kesarwani
Manjunath G Javoor
Kutti R Vinothkumar
Minhajuddin Sirajuddin

Keywords

Humans
Models, Molecular
Cryoelectron Microscopy
Actins