Fluorescent proteins for photoactivation experiments.

The discoveries, improvements, and alterations of fluorescent protein (FP) variants are having a profound impact on the ability of investigators to observe and quantify the behavior of proteins within cells and organisms. Among the most promising of FPs are photoactivatable fluorescent proteins (PA-FPs). Invisible at the imaging wavelength until activated by irradiation at a different wavelength, PA-FPs allow the controlled highlighting of distinct molecular populations within the cell. This chapter introduces the different types of PA-FPs and discusses their use for monitoring protein movement, protein turnover, protein interactions, and high-resolution protein localization.