Expansins and expansin-like proteins revisited: Untangling the 'Gordian' knots.

Expansins and expansin-like proteins influence cell wall properties across diverse organisms, with recent discoveries revealing catalytic activity in some members of the superfamily.

• Why it matters: Understanding ESPs is crucial because they play key roles in cell wall growth, pathogen virulence, and microbial decomposition, yet their mechanisms and functions remain complex and not fully clarified.
• What they did: The review synthesizes biomechanical and biochemical data on ESPs, examines substrate-binding affinities, refines their nomenclature, and discusses assays used to evaluate their activity, including recent findings of catalytic functions.
• The result: This work advances the understanding of ESP functions, highlights challenges in activity assessment, and aims to stimulate further research into their diverse roles and mechanisms in cell wall dynamics.