A compact set of sea star footprint proteins mediates the adhesion of Asterina gibbosa

Abstract Sea stars achieve strong yet reversible underwater adhesion using a duo-gland system in their tube feet. While adhesive footprint proteins (Sfps) are well characterized in Asterias rubens, comparable molecular data for other asteroids are limited. Here, we generated a high-quality de novo genome assembly of the starlet cushion star, Asterina gibbosa, enabling full-length gene identification of Sfps. Proteomics of deposited footprint material identified 34 candidates; in situ hybridization localized 10 to the tube foot adhesive epidermis. Nine (designated Agib-Sfps) were homologous to known A. rubens Sfps and one encoded a trypsin-like proteinase. Anti-peptide antibodies revealed distinct footprint labelling patterns for Agib-Sfp7 and Agib-Sfp8, although mostly associated to the thin layer in contact with the substrate. Comparative analyses indicate a conserved core adhesive toolkit and domain repertoire between species, alongside species-specific reshuffling of domains across Sfps. These results refine the molecular model of asteroid adhesion and provide targets for sequence recombinant production toward seawater-compatible biomimetic adhesives.