Probing plant membranes with FM dyes: tracking, dragging or blocking?

• Published in: The Plant journal : for cell and molecular biology Vol. 61; no. 5; pp. 883 - 892
• Main Authors: Jelínková, Adriana, Malínská, Kateřina, Simon, Sibu, Kleine‐Vehn, Jürgen, Pařezová, Markéta, Pejchar, Přemysl, Kubeš, Martin, Martinec, Jan, Friml, Jiří, Zažímalová, Eva, Petrášek, Jan
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.03.2010; Blackwell
• Subjects: Arabidopsis - cytology; Biological and medical sciences; Cell Line; Cell Membrane - chemistry; Cell physiology; Dyes; Endocytosis; Flowers & plants; Fluorescent Dyes - pharmacology; FM 1‐43; FM 4‐64; Fundamental and applied biological sciences. Psychology; Indoleacetic Acids - metabolism; Membranes; Molecular and cellular biology; Plant physiology and development; Plant populations; Plant Proteins - drug effects; plasma membrane; Protein Transport; Pyridinium Compounds - pharmacology; Quaternary Ammonium Compounds - pharmacology; tobacco BY‐2 cells; Endocytosis; Plant; Vegetals; Dyes; FM 4-64; tobacco BY-2 cells; Plasma membrane; FM 1-43; Blocking; Cell
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2009.04102.x

Summary Remarkable progress in various techniques of in vivo fluorescence microscopy has brought an urgent need for reliable markers for tracking cellular structures and processes. The goal of this manuscript is to describe unexplored effects of the FM (Fei Mao) styryl dyes, which are widely used probes that label processes of endocytosis and vesicle trafficking in eukaryotic cells. Although there are few reports on the effect of styryl dyes on membrane fluidity and the activity of mammalian receptors, FM dyes have been considered as reliable tools for tracking of plant endocytosis. Using plasma membrane‐localized transporters for the plant hormone auxin in tobacco BY‐2 and Arabidopsis thaliana cell suspensions, we show that routinely used concentrations of FM 4‐64 and FM 5‐95 trigger transient re‐localization of these proteins, and FM 1‐43 affects their activity. The active process of re‐localization is blocked neither by inhibitors of endocytosis nor by cytoskeletal drugs. It does not occur in A. thaliana roots and depends on the degree of hydrophobicity (lipophilicity) of a particular FM dye. Our results emphasize the need for circumspection during in vivo studies of membrane proteins performed using simultaneous labelling with FM dyes.