Sulfated plant peptide hormones

Abstract

Sulfated peptides are plant hormones that are active at nanomolar concentrations. The sulfation at one or more tyrosine residues is catalysed by tyrosylprotein sulfotransferase (TPST), which is encoded by a single-copy gene. The sulfate group is provided by the co-substrate 3´-phosphoadenosine 5´-phosphosulfate (PAPS), which links synthesis of sulfated signaling peptides to sulfur metabolism. The precursor proteins share a conserved DY-motif that is implicated in specifying tyrosine sulfation. Several sulfated peptides undergo additional modification such as hydroxylation of proline and glycosylation of hydroxyproline. The modifications render the secreted signaling molecules active and stable. Several sulfated signaling peptides have been shown to be perceived by leucine-rich repeat receptor-like kinases (LRR-RLKs) but have signaling pathways that, for the most part, are yet to be elucidated. Sulfated peptide hormones regulate growth and a wide variety of developmental processes, and intricately modulate immunity to pathogens. While basic research on sulfated peptides has made steady progress, their potential in agricultural and pharmaceutical applications has yet to be explored.

The Sequenced Genomes of Non-Flowering Land Plants Reveal the (R)Evolutionary History of Peptide Signaling

“…To address this hypothesis, we started by going through literature and data on peptide signaling and LRXI. A number of papers have reviewed specific peptide or receptor families involved in peptide signaling (Fernandez et al, 2013; Muschietti and Wengier, 2018; Oh et al, 2018; Taleski et al, 2018; Kaufmann and Sauter, 2019; Segonzac and Monaghan, 2019; Shi et al, 2019) and (Supplemental Table 2). It has not been, however, comprehensively investigated how widely these receptors and ligands are conserved; here we identified the need to search for homologues of Arabidopsis LRXI genes in non-flowering plants as well as genes encoding specific peptides to match the presence of their presumptive receptors.…”

“…In Arabidopsis, Tyr sulfation regulates protein-protein interactions and affects receptor binding (Matsubayashi and Sakagami, 1996; Shinohara et al, 2016; Kaufmann and Sauter, 2019). The gene encoding the responsible enzyme, TYROSYLPROTEIN SULFOTRANSFERASE ( AtTPST ), was discovered in Arabidopsis (Komori et al, 2009).…”

“…PSY1 has an N-terminal DY sulf , and promotes cellular proliferation and expansion (Amano et al, 2007). The mature PSK peptide is only five amino acids long (YIYIQ) and promotes cell growth, acts in the root apical meristem, contributes to pollen tube guidance, and integrates growth and defense (Sauter, 2015; Kaufmann and Sauter, 2019). We identified putative orthologues both for PSY1 and PSK in P. patens, M. polymorpha as well as P. abies (Figure 5D-E).…”

Controlling the Heterodimerisation of the Phytosulfokine Receptor 1 (PSKR1) via Island Loop Modulation

“…One of such hormones is phytosulfokine (PSK): a sulfated peptide which is biologically active in nanomolar concentrations [5,6]. Comprised of five residues (Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln) [7,8], of which both tyrosines are sulfated, PSK has been classified as a crucial plant growth factor [3,9,10].…”

“…Its main binding partners are the phytosulfokine receptors (PSKR) [12,13]. These receptors were first identified on Daucus carrota, and its gene is conserved among different plants species [7,10]. One of these is Arabidopsis thaliana, which expresses two different orthologues: PSKR1 [14] and PSKR2 [15], with the PSK sensing occurring mainly through PSKR1 [15].…”