Structural highlights
Function
CITA_KLEPN Member of the two-component regulatory system CitA/CitB. Probably activates CitB by phosphorylation. The periplasmic domain binds H-citrate(2-), which is essential for induction of the citrate-fermentation genes.[1] GFP_AEQVI Energy-transfer acceptor. Its role is to transduce the blue chemiluminescence of the protein aequorin into green fluorescent light by energy transfer. Fluoresces in vivo upon receiving energy from the Ca(2+)-activated photoprotein aequorin.
Publication Abstract from PubMed
Motivated by the growing recognition of citrate as a central metabolite in a variety of biological processes associated with healthy and diseased cellular states, we have developed a series of high-performance genetically encoded citrate biosensors suitable for imaging of citrate concentrations in mammalian cells. The design of these biosensors was guided by structural studies of the citrate-responsive sensor histidine kinase and took advantage of the same conformational changes proposed to propagate from the binding domain to the catalytic domain. Following extensive engineering based on a combination of structure guided mutagenesis and directed evolution, we produced an inverse-response biosensor (DeltaF/F min approximately 18) designated Citroff1 and a direct-response biosensor (DeltaF/F min approximately 9) designated Citron1. We report the X-ray crystal structure of Citron1 and demonstrate the utility of both biosensors for qualitative and quantitative imaging of steady-state and pharmacologically perturbed citrate concentrations in live cells.
High-Performance Intensiometric Direct- and Inverse-Response Genetically Encoded Biosensors for Citrate.,Zhao Y, Shen Y, Wen Y, Campbell RE ACS Cent Sci. 2020 Aug 26;6(8):1441-1450. doi: 10.1021/acscentsci.0c00518. Epub, 2020 Jul 9. PMID:32875085[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kaspar S, Perozzo R, Reinelt S, Meyer M, Pfister K, Scapozza L, Bott M. The periplasmic domain of the histidine autokinase CitA functions as a highly specific citrate receptor. Mol Microbiol. 1999 Aug;33(4):858-72. PMID:10447894
- ↑ Zhao Y, Shen Y, Wen Y, Campbell RE. High-Performance Intensiometric Direct- and Inverse-Response Genetically Encoded Biosensors for Citrate. ACS Cent Sci. 2020 Aug 26;6(8):1441-1450. doi: 10.1021/acscentsci.0c00518. Epub, 2020 Jul 9. PMID:32875085 doi:http://dx.doi.org/10.1021/acscentsci.0c00518
