Addgene
pTRE_GFP-GluR1
Dronpa
Dronpa is a reversibly switchable photoactivatable fluorescent protein that is 2.5 times as bright as EGFP.[1][2] Dronpa gets switched off by strong illumination with 488 nm (blue) light and this can be reversed by weak 405 nm UV light.[1] A single dronpa molecule can switched on and off over 100 times.[3] It has an excitation peak at 503 nm and an emission peak at 518 nm.
A tetrameric,[4] reversibly switchable fluorescent protein was discovered in a cDNA screen of a stony coral (Pectiniidae). A monomeric variant of this protein was named "Dronpa" after "Dron" a ninja term for vanishing and pa for photoactivation.[2]
Dronpa is 257 amino acids long and is a 28.8 kDa monomer. Dronpa is 76% similar in sequence to GFP[2] and shares a similar structure with an 11 stranded β-barrel (a β-can) enclosing an α-helix.[5] The chromophore is formed autocatalytically from residues Cys62,Tyr63 and Gly64.[5][6] The on state of the dronpa molecule has the chromophore in a cis conformation while the off state chromophore exists in the trans conformation. Several other residues in the vicinity of the chromophore also move during the on-off transition resulting a very different electrostatic environment.[5]
Applications
Dronpa's fast dynamics and stability under repeated cycles of switching make it one of the more important switchable fluorescent proteins.[1] It is used in super resolution microscopy techniques like PALM/STORM. It can also be used to track fast dynamics of proteins in cells.
When a weakly tetrameric form of Dronpa photoswitches, its oligomerization affinity changes. This was used to enable optical control over the activity of enzymes. Specifically, two Dronpa domains attached to the ends of a protein oligomerized and blocked enzyme activity in the dark, but monomerized after illumination, enabling enzyme activity.[4]
References
- ↑ 1.0 1.1 1.2 doi:10.1039/b901966a
This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand - ↑ 2.0 2.1 2.2 doi:10.1126/science.1102506
This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand - ↑ doi:10.1073/pnas.0500489102
This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand - ↑ 4.0 4.1 doi:10.1126/science.1226854
This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand - ↑ 5.0 5.1 5.2 doi:10.1073/pnas.0700629104
This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand - ↑ doi:10.1042/BJ20061401
This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand