POLARIS is a copper-binding peptide that interacts with ETR1 to negatively regulate ethylene signaling in Arabidopsis.

ABSTRACT: Ethylene signaling is one of the classic hormonal pathways in plants, with diverse roles in development and stress responses. The dimeric ethylene receptor localizes to the endoplasmic reticulum and contains Cu(I) ions essential for ethylene binding and signal transduction. We previously discovered that mutants of the Arabidopsis gene POLARIS (PLS), encoding a 36-amino-acid peptide, exhibit enhanced ethylene signaling responses suggestive of reduced receptor activity, but the role and activity of the PLS peptide in this signaling cascade have not been defined. Here, we report that Arabidopsis PLS binds copper as a 1:2 thiol-dependent Cu(I):PLS₂ complex with an affinity of 3.79 (±1.5) × 10¹⁹ M^-2 via two cysteine residues conserved in the related species Came

SUBMITTER: Mudge AJ 

PROVIDER: S-EPMC12744750 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature