A GFP‐mouse talin fusion protein labels plant actin filaments in vivo and visualizes the actin cytoskeleton in growing pollen tubes

• Published in: The Plant journal : for cell and molecular biology 1998-11, Vol.16 (3), p.393-401
• Main Authors: Kost, Benedikt, Spielhofer, Pius, Chua, Nam‐Hai
• Format: Article
• Language: English
• Subjects: Actins - metabolism; Animals; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis thaliana; Biological and medical sciences; Cell Line; Cytoskeleton - metabolism; Fundamental and applied biological sciences. Psychology; General aspects; Green Fluorescent Proteins; Luminescent Proteins - metabolism; Mice; Nicotiana - metabolism; Plant physiology and development; Plants, Genetically Modified; Plants, Toxic; Recombinant Fusion Proteins - metabolism; Talin - metabolism; Vegetative and sexual reproduction, floral biology, fructification
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313x.1998.00304.x

Summary The C‐terminus of mouse talin (amino acids 2345–2541) is responsible for all of the protein’s f‐actin binding capacity. Unlike full‐length talin, the C‐terminal f‐actin binding domain is unable to nucleate actin polymerization. We have found that transient and stable expression of the talin actin‐binding domain fused to the C‐terminus of the green fluorescent protein (GFP‐mTn) can visualize the actin cytoskeleton in different types of living plant cells without affecting cell morphology or function. Transiently expressed GFP‐mTn co‐localized with rhodamine‐phalloidin in permeabilized tobacco BY‐2 suspension cells, showing that the fusion protein can specifically label the plant actin cytoskeleton. Constitutive expression of GFP‐mTn in transgenic Arabidopsis thaliana plants visualized actin filaments in all examined tissues with no apparent effects on plant morphology or development at any stage during the life cycle. This demonstrates that in a number of different cell types GFP‐mTn can serve as a non‐invasive marker for the actin cytoskeleton. Confocal imaging of GFP‐mTn labeled actin filaments was employed to reveal novel information on the in vivo organization of the actin cytoskeleton in transiently transformed, normally elongating tobacco pollen tubes.