Misshapen coordinates protrusion restriction and actomyosin contractility during collective cell migration

Area of Science:

• Cell Biology
• Developmental Biology
• Biochemistry

Background:

• Collective cell migration is crucial for development, wound healing, and metastasis.
• In Drosophila, border cells (BC) migrate collectively, requiring coordinated protrusion formation and rearward contractility for directed motility.
• The actin-binding protein Moesin is essential for restricting protrusions to leader cells.

Purpose of the Study:

• To investigate the role of the Ste20-like kinase Misshapen (Msn) in regulating collective cell migration.
• To determine how Msn influences Moesin activity and its impact on border cell protrusion and contractility.

Main Methods:

• In vitro kinase assays to assess Moesin phosphorylation by Msn.
• In vivo experiments using Drosophila border cells to study Msn's function.
• Depletion of Msn to observe effects on cell protrusion and cluster contractility.

Main Results:

• Misshapen phosphorylates Moesin in vitro and in border cells.
• Msn depletion disrupts protrusion restriction, leading to ectopic protrusions in non-leader cells.
• Msn is critical for generating contractile forces at the rear of the cell cluster and at protrusion bases.

Conclusions:

• Misshapen is a key regulator of collective cell migration in Drosophila border cells.
• Msn coordinates two distinct pathways: restricting protrusions to leader cells and inducing contractile forces.
• This dual role of Msn ensures directed collective cell migration.