The class VIII myosin ATM2 stabilizes actin-plasma membrane contacts in tobacco pollen tubes by locally promoting PtdIns(4,5)P(2) formation.

ATM2 stabilizes actin-PM contacts in tobacco pollen tubes by locally promoting PtdIns(4,5)P2 nanodomain formation, affecting actin dynamics and pollen tube morphology.

• Why it matters: Understanding how actin filaments interact with the plasma membrane in plant cells is limited, especially regarding lipid-protein interactions that regulate this contact. Clarifying ATM2’s role could reveal mechanisms underlying actin stabilization and membrane organization in plant growth.
• What they did: The study used tobacco pollen tube cells to investigate ATM2’s lipid-binding properties, its interaction with PIP5K2, and its effect on PtdIns(4,5)P2 levels, employing overexpression, lipid depletion, and in vitro assays to analyze actin and lipid dynamics.
• The result: ATM2 overexpression extended PtdIns(4,5)P2-rich membrane regions and enhanced PIP5K2 activity, indicating ATM2’s role in promoting PtdIns(4,5)P2 nanodomain formation, which stabilizes actin at the membrane interface.