The F-BAR Domain of Rga7 Relies on a Cooperative Mechanism of Membrane Binding with a Partner Protein during Fission Yeast Cytokinesis

Abstract

SUMMARYF-BAR proteins bind the plasma membrane (PM) to scaffold and organize the actin cytoskeleton. To understand how F-BAR proteins achieve their PM association, we studied the localization of a Schizosaccharomyces pombe F-BAR protein Rga7, which requires the coiled-coil protein Rng10 for targeting to the division site during cytokinesis. We find that the Rga7 F-BAR domain directly binds a motif in Rng10 simultaneously with the PM, and that an adjacent Rng10 motif independently binds the PM. Together, these multivalent interactions significantly enhance Rga7 F-BAR avidity for membranes at physiological protein concentrations, ensuring the division site localization of Rga7. Moreover, the requirement for the F-BAR domain in Rga7 localization and function in cytokinesis is bypassed by tethering an Rga7 construct lacking its F-BAR to Rng10, indicating that at least some F-BAR domains are necessary but not sufficient for PM targeting and are stably localized to specific cortical positions through adaptor proteins.

The intrinsically disordered region of the cytokinetic F-BAR protein Cdc15 performs a unique essential function in maintenance of cytokinetic ring integrity

“…, 2015; Garabedian et al. , 2018; Liu et al. , 2019), including Cdc15’s F-BAR domain that binds the formin Cdc12 (Willet et al.…”

Coordinating septum formation and the actomyosin ring during cytokinesis in Schizosaccharomyces pombe

“…Rga7 is a Rho2 GTPase‐activating protein (GAP), but the catalytic activity is not required for its role in cytokinesis (Soto et al , ; Martin‐Garcia et al , ). Rga7 interacts with Rng10, a coiled coil protein that enables it to interact with the membrane at the division site and promote ring stability (Liu et al , ). Rga7 has been shown to specifically promote Bgs4 recruitment to the division site (Arasada and Pollard, ).…”

Regulación de la citoquinesis por Rgf1 y la ruta de integridad

“…La localización de Rgf3 también depende de la arrestina Art1, con quien interactúa físicamente y en cuyo mutante la maduración y constricción son más lentas (Davidson et al 2015). Rga7 es reclutado a la membrana por la proteína coiled-coil Rng10 también en esta etapa, y ambas regulan la localización de la β-glucán sintasa Bgs4 durante la septación (Liu et al 2016(Liu et al , 2019.…”