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ABSTRACT Posttranslational tyrosine sulfation of peptides and proteins is catalysed by tyrosylprotein sulfotransferases (TPSTs). InArabidopsis, tyrosine sulfation is essential for the activities of peptide hormones, such as phytosulfokine (PSK) and root meristem growth factor (RGF). Here, we identified a TPST‐encoding gene,MtTPST, from model legumeMedicago truncatula.MtTPSTexpression was detected in all organs, with the highest level in root nodules. Apromoter:GUSassay revealed thatMtTPSTwas highly expressed in the root apical meristem, nodule primordium and nodule apical meristem. The loss‐of‐function mutantmttpstexhibited a stunted phenotype with short roots and reduced nodule number and size. Application of both of the sulfated peptides PSK and RGF3 partially restored the defective root length ofmttpst. The reduction in symbiotic nodulation inmttpstwas partially recovered by treatment with sulfated PSK peptide. MtTPST‐PSK module functions downstream of the Nod factor signalling to promote nodule initiation via regulating accumulation and/or signalling of cytokinin and auxin. Additionally, the small‐nodule phenotype ofmttpst, which resulted from decreased apical meristematic activity, was partially complemented by sulfated RGF3 treatment. Together, these results demonstrate that MtTPST, through its substrates PSK, RGF3 and other sulfated peptide(s), positively regulates nodule development and root growth.
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A Bacterial Sulfotransferase Catalyzes an Unusual Di‐Sulfation in Natural Products Biosynthesis
Sulfation is a widely used strategy in nature to modify the solubility, polarity, and biological activities of molecules. The enzymes catalyzing sulfation, sulfotransferases (STs), are typically highly specific to a single sulfation site in a molecule. Herein, the identification and characterization of sulfated adipostatins is reported and reveals a novel sulfotransferase, AdpST, which is responsible for di‐sulfation at two sites of adipostatins. The initial bioinformatic analysis in search of adipostatin analogs fromStreptomyces davaonensisDSM101723 identifiesadpSTand a 3’‐phosphoadenosine‐5’‐phosphosulfate (PAPS) biosynthetic cassette, which are co‐clustered with the adipostatin‐encoding type III polyketide synthase. Mono‐ and di‐sulfated adipostatin analogs are discovered in the extracts ofS. davaonensisDSM101723, whereas di‐sulfated bacterial natural products has not been reported. Using a series of in vivo and in vitro experiments, it is confirmed that AdpST is solely responsible for both mono‐ and di‐sulfation of adipostatins, a catalytic activity which has not been identified in bacterial PAPS‐dependent STs to date. It is further demonstrated that the dedicated PAPS biosynthetic cassette improves di‐sulfation capacity. Lastly, it is determined that AdpST shares similarity with a small group of uncharacterized STs, suggesting the presence of additional unique bacterial STs in nature, and that AdpST is phylogenetically distant from many characterized STs.
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- Award ID(s):
- 2216137
- PAR ID:
- 10601146
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemBioChem
- Volume:
- 26
- Issue:
- 11
- ISSN:
- 1439-4227
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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