Acid-Tolerant Monomeric GFP from Olindias formosa. Issue 3 (15th March 2018)

• Record Type: Journal Article
• Authors: Shinoda, Hajime; Ma, Yuanqing; Nakashima, Ryosuke; Sakurai, Keisuke; Matsuda, Tomoki; Nagai, Takeharu
• Is Part Of: Cell chemical biology. Volume 25:Issue 3(2018)
• Page Start: 330
• Page End: 338.e7
• Publication Date: 2018-03-15
• Subjects: GFP -- fluorescent protein -- acid tolerance -- pH insensitive -- acidic organelles -- lysosome -- multicolor imaging -- flower hat jellyfish -- monomer -- quantum yield; Biochemistry -- Periodicals; 572.05
• DOI: 10.1016/j.chembiol.2017.12.005
• Languages: English
• ISSNs: 2451-9456

Abstract

Summary: The fluorescent protein (FP) color palette has greatly contributed to the visualization of molecular and cellular processes. However, most FPs lose fluorescence at a pH lower than their neutral p K a (∼6), and this has hampered their application in acidic organelles (pH ∼4.5–6.0). Currently, several cyan- and red-colored acid-tolerant FPs are available; however, there are few reports of acid-tolerant green FPs (GFPs) that are practically applicable to bioimaging. Here, we developed the acid-tolerant monomeric GFP "Gamillus" from the jellyfish Olindias formosa, with excellent brightness, maturation speed, and photostability. Results from X-ray crystallography and point mutagenesis suggest that across a broad pH range the acid tolerance is attributed to stabilization of deprotonation in the chromophore phenyl ring by forming a unique trans configuration. We demonstrate that Gamillus can serve as a molecular tag suitable for imaging in acidic organelles through autophagy-mediated molecular tracking to lysosomes. Graphical Abstract: Highlights: The acid-tolerant monomeric GFP "Gamillus" has p K a of 3.4 Gamillus shows excellent brightness, chromophore maturation speed, and photostability Gamillus adapts trans isomeric conformation of the chromophore phenyl ring Gamillus is a good molecular tag for studying biological event in acidic compartment Abstract : Shinoda et al. describe the cloning, engineering, and characterization of a monomeric GFP "Gamillus" from Olindias formosa . Gamillus has superior acid tolerance (p K a = 3.4) to reported other monomeric GFPs, and a unique trans chromophore configuration contributed to the acid tolerance. They demonstrate the usefulness for imaging in an acidic cellular environment, e.g., lysosomes.