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Abstract H2S is a gaseous signaling molecule that modifies cysteine residues in proteins to form persulfides (P‐SSH). One family of proteins modified by H2S are zinc finger (ZF) proteins, which contain multiple zinc‐coordinating cysteine residues. Herein, we report the reactivity of H2S with a ZF protein called tristetraprolin (TTP). Rapid persulfidation leading to complete thiol oxidation of TTP mediated by H2S was observed by low‐temperature ESI‐MS and fluorescence spectroscopy. Persulfidation of TTP required O2 , which reacts with H2S to form superoxide, as detected by ESI‐MS, a hydroethidine fluorescence assay, and EPR spin trapping. H2S was observed to inhibit TTP function (binding to TNFα mRNA) by an in vitro fluorescence anisotropy assay and to modulate TNFα in vivo. H2S was unreactive towards TTP when the protein was bound to RNA, thus suggesting a protective effect of RNA.
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Targeting Zinc Finger Proteins with Exogenous Metals and Molecules: Lessons Learned from Tristetraprolin, a CCCH type Zinc Finger
Abstract ZF proteins are ubiquitous eukaryotic proteins that play important roles in gene regulation. ZFs contain small domains made up of a combination of four cysteine and histidine residues and are classified on the basis of the identity of these residues and their spacing. One emerging class of ZFs are the Cys3His (or CCCH) class of ZFs. These ZFs play key roles in regulating RNA. In this minireview, an overview of the CCCH class of ZFs, with a focus on tristetraprolin (TTP), is provided. TTP regulates inflammation by controlling cytokine mRNAs, and there is an interest in modulating TTP activity to control inflammation. Two methods to control TTP activity are to target with exogenous metals (a “metals in medicine” approach) or to target with endogenous signaling molecules. Work that has been done to target TTP with Fe, Cu, Cd, and Au as well as with H2S is reviewed. This includes attention to new methods that have been developed to monitor metal exchange with the spectroscopically silent ZnIIincluding native electro‐spray ionization mass spectrometry (ESI‐MS), spin‐filter inductively coupled plasma mass spectrometry (ICP‐MS), and cryo‐electro‐spray mass spectrometry (CSI‐MS); along with fluorescence anisotropy (FA) to follow RNA binding.
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- Award ID(s):
- 1708732
- PAR ID:
- 10277989
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- European Journal of Inorganic Chemistry
- Volume:
- 2021
- Issue:
- 37
- ISSN:
- 1434-1948
- Format(s):
- Medium: X Size: p. 3795-3805
- Size(s):
- p. 3795-3805
- Sponsoring Org:
- National Science Foundation
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