Two-color photoactivatable probe for selective tracking of proteins and cells

Abstract

We report the development and application of photoactivatable Green Cherry (GPAC), the first genetically encoded "continuously red-photoactivatable green" two-color probe for live cell imaging. G PAC is unique in that it enables real-time tracking of selected subpopulations of proteins and organelles in the cell or of cells within tissues and whole organisms, with constant reference to the entire population of the probe. Using GPAC-zyxin as proof of utility, we obtained new insights into the dynamic movement of the cytoskeletal protein zyxin.Weshow that zyxin is continuously and rapidly recruited from the cytosol into established focal adhesions. It can also move rapidly within a given focal adhesion and "hop" between adjacent focal adhesions, emphasizing the dynamic nature of proteins within these structures. The in vivo utility of GPAC is exemplified by tracking hemocyte movements using a versatile transgenic Drosophila model engineered to express GPAC in tissues and cells of interest under the control of the GAL4-inducible promoter. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.