P. Lappalainen

Specialized actin nanoscale layers control focal adhesion turnover

The paper identifies two new nanoscale actin layers in focal adhesions, showing their distinct roles in adhesion maturation and disassembly through Tpm1.6 and Tpm3.2.

Unusual actin-binding mechanism and the role of profilin in actin dynamics of trypanosomatid parasites

This study identifies a unique actin-binding mechanism of profilin in trypanosomatid parasites, revealing its role in actin dynamics and potential as a drug target.

SARS-CoV-2 infected cells sprout actin-rich filopodia that facilitate viral invasion

This study shows SARS-CoV-2 uses actin-rich filopodia for efficient viral entry, revealing two modes of entry and identifying potential antiviral targets.

Recycling limits the lifetime of actin turnover

This study investigates how actin turnover is sustained with a limited monomer pool by analyzing bead motility and identifying recycling as a key factor.

Structural basis underlying specific biochemical activities of non-muscle tropomyosin isoforms

The paper determines cryo-EM structures of actin filaments with two non-muscle tropomyosin isoforms, revealing structural differences that explain their distinct functional roles.

Activated I-BAR IRSp53 clustering controls the formation of VASP-actin-based membrane protrusions

The paper investigates how IRSp53 clustering regulates filopodia initiation by recruiting VASP to form actin-based membrane protrusions.

A myosin chaperone, UNC-45A, is a novel regulator of intestinal epithelial barrier integrity and repair

This study identifies UNC-45A as a regulator of intestinal epithelial barrier integrity and repair, showing its role in maintaining junctions and contractile forces.

Full assembly of HIV-1 particles requires assistance of the membrane curvature factor IRSp53.

This study shows that IRSp53 assists HIV-1 in forming membrane curvature necessary for complete particle assembly.

Conformational dynamics regulate SHANK3 actin and Rap1 binding

This study shows SHANK3 binds actin and Rap1 through its SPN domain, with conformational changes regulating this interaction and affecting cellular processes like filopodia formation and autism-related phenotypes.

Generation of stress fibers through myosin-driven re-organization of the actin cortex

The paper identifies a new mechanism for stress fiber formation through myosin-driven re-organization of the actin cortex, independent of pre-existing actomyosin bundles.

Twinfilin uncaps filament barbed ends to promote turnover of lamellipodial actin networks

This study identifies twinfilin as a regulator of capping protein dynamics in actin networks, showing it promotes CP dissociation and filament turnover in cells.

Ezrin enrichment on curved membranes requires a specific conformation or interaction with a curvature-sensitive partner

This study investigates how ezrin enrichment on curved membranes depends on its conformation or interaction with curvature-sensitive partners, showing that specific conformations and binding to I-BAR-domain proteins enable targeting to curved membranes.