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

Expansins and expansin-like proteins are diverse cell wall-loosening proteins present across multiple organisms, with recent discoveries revealing catalytic activity in some ESPs.

• Why it matters: Understanding ESPs' roles is crucial because they influence cell wall properties, pathogenicity, and microbial decomposition, yet their mechanisms and activities remain incompletely characterized.
• What they did: The review provides a biomechanical overview of ESPs' effects on cell wall properties, examines substrate-binding affinities, refines ESP nomenclature, and discusses assays and challenges in evaluating ESP activity.
• The result: This work aims to stimulate further research into ESP functions and activities, potentially leading to new insights into cell wall dynamics and microbial or plant interactions.