Anillin forms linear structures and facilitates furrow ingression after septin and formin depletion
Mikhail Lebedev,
Fung-Yi Chan,
Anna Lochner,
Jennifer Bellessem,
Daniel S. Osório,
Elisabeth Rackles,
Tamara Mikeladze-Dvali,
Ana Xavier Carvalho,
Esther Zanin
Affiliations
Mikhail Lebedev
Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Biologie, 91058 Erlangen, Germany; Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
Fung-Yi Chan
i3S - Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
Anna Lochner
Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Biologie, 91058 Erlangen, Germany
Jennifer Bellessem
Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
Daniel S. Osório
i3S - Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
Elisabeth Rackles
Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
Tamara Mikeladze-Dvali
Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany
Ana Xavier Carvalho
i3S - Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
Esther Zanin
Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Biologie, 91058 Erlangen, Germany; Department Biologie, Ludwig-Maximilians University, Munich, 82152 Planegg-Martinsried, Germany; Corresponding author
Summary: During cytokinesis, a contractile ring consisting of unbranched filamentous actin (F-actin) and myosin II constricts at the cell equator. Unbranched F-actin is generated by formin, and without formin no cleavage furrow forms. In Caenorhabditis elegans, depletion of septin restores furrow ingression in formin mutants. How the cleavage furrow ingresses without a detectable unbranched F-actin ring is unknown. We report that, in this setting, anillin (ANI-1) forms a meshwork of circumferentially aligned linear structures decorated by non-muscle myosin II (NMY-2). Analysis of ANI-1 deletion mutants reveals that its disordered N-terminal half is required for linear structure formation and sufficient for furrow ingression. NMY-2 promotes the circumferential alignment of the linear ANI-1 structures and interacts with various lipids, suggesting that NMY-2 links the ANI-1 network with the plasma membrane. Collectively, our data reveal a compensatory mechanism, mediated by ANI-1 linear structures and membrane-bound NMY-2, that promotes furrowing when unbranched F-actin polymerization is compromised.
