Over the past decade, fluorescent proteins have launched a new and unprecedented era in cell biology by enabling investigators to apply routine molecular cloning methods, fusing these optical probes to a wide variety of protein and enzyme targets, in order to monitor cellular processes in living systems using fluorescence microscopy and related methodology. The spectrum of applications for fluorescent proteins ranges from reporters of transcriptional regulation and targeted markers for organelles and other subcellular structures to fusion proteins designed to monitor motility and dynamics. These fascinating probes have also opened the door to creating biosensors for numerous intracellular phenomena, including pH and ion concentration fluctuations, protein kinase activity, apoptosis, voltage, and cyclic nucleotide signaling. By applying selected promoters and targeting signals, fluorescent protein biosensors can be introduced into an intact organism and directed to a host of specific tissues, cell types, as well as subcellular compartments to enable an unprecedented focus on monitoring a variety of physiological processes.
Fluorescent Protein Review Articles - The growing class of fluorescent proteins useful for detecting events in living cells and animals has almost single-handedly launched and fueled a new era in biology and medicine. These powerful research tools have provided investigators with a mechanism of fusing a genetically encoded optical probe to a practically unlimited variety of protein targets in order to examine living systems using fluorescence microscopy and related technology. The references listed in this section point to review articles that should provide the starting point for a thorough understanding of fluorescent protein technology.
Optical Highlighter Fluorescent Protein Original References - Optical highlighter fluorescent proteins, which include the photoactivatable GFP (PA-GFP), the green-to-red photoconverter Kaede, and the photoswitchable Dronpa, allow direct and controlled activation of distinct molecular pools of the fluorescent proteins within the cell. Listed in this section are key references to many of the original articles describing the discovery and properties of optical highlighters.
Photoactivation and Photoconversion - The ability to selectively initiate or alter fluorescence emission profiles in fluorescent proteins has resulted in the creation of a new class of probes for exploring protein behavior and dynamics in living cells. As the fluorescence intensity or spectral alterations of highlighters generally occur only after photon-mediated conversion, newly synthesized non-photoactivated protein pools remain unobserved and do not complicate experimental results. This section provides sources for selected review articles and original research reports on optical highlighter fluorescent proteins.
Fluorescent Protein FRET Biosensors - Aside from their utility as fusion partners to report on protein localization in multiple colors, fluorescent proteins have also been cleverly used to create highly specific biosensors to monitor a wide spectrum of physiological processes, including pH fluctuations, calcium wave induction, cyclic nucleotide messenger effects, membrane potential differences, signaling, phosphorylation, redox reactions, and apoptosis.
Aequorea victoria (Jellyfish) Fluorescent Proteins - Explore the early research reports involved with elucidating the structure and function of luminescent and fluorescent proteins derived from the Pacific jellyfish, Aequorea victoria. Papers by Osamu Shimomura, Martin Chalfie, and Roger Tsien described research that eventually resulted in the 2008 Nobel Prize in Chemistry being awarded to these investigators.
Anthozoa (coral) Fluorescent Proteins - The search for a red-emitting fluorescent protein with performance attributes similar to those of the enhanced green fluorescent protein (EGFP) from the Aequorea victoria jellyfish (in effect, brightness, photostability, and utility in fusions) has been seen as a critical avenue to providing an important tool for multicolor imaging and in generating new fluorescence resonance energy transfer (FRET) biosensors with spectral profiles in the longer wavelengths.
Fluorescent Protein Engineering - As a class, fluorescent proteins have been subjected to more extensive protein engineering and artificial directed evolution than almost any other category of protein. Such a concentrated effort on these probes is due to the fact that fluorescent proteins are extremely popular tools in the biological sciences and improved variants can provide huge benefits to researchers.