Characterization of phalloidin‐negative nuclear actin filaments in U2OS cells expressing cytoplasmic actin‐EGFP

• DOI: 10.1111/gtc.12930
• Publication Date: 2022-02-23T09:05:59Z
• Authors: Akira Nagasaki; Kaoru Katoh; Masamichi Hoshi; Motomichi Doi; Chikashi Nakamura; Taro Q. P. Uyeda
• Keywords: Actin remodeling; Phalloidin; Cofilin; MDia1; Profilin; Actin-binding protein; Treadmilling

Actin is a major structural component of the cytoskeleton in eukaryotic cells, including fungi, plants, and animals, exists not only cytoplasm as but also nucleus. Recently, we developed novel actin probe, β-actin-EGFP fusion protein, which exhibited similar monomeric to filamentous ratio that endogenous actin, contrast widely used EGFP-β-actin protein over-assembles cells. Unexpectedly, this probe visualized an interconnected meshwork slightly curved beam-like bundles filaments nucleus U2OS These structures were labeled with rhodamine phalloidin, Lifeact-EGFP or anti-actin antibodies. In addition, immunofluorescence staining expression cofilin-EGFP revealed nuclear contained cofilin. We named these phalloidin-negative intranuclear (PHANIN) filaments. Since PHANIN could be detected by general detection methods for filaments, propose are different from previously reported structures.