Abl kinases regulate actin comet tail elongation via an N-WASP-dependent pathway

Area of Science:

• Microbiology
• Cell Biology
• Biochemistry

Background:

• Microbial pathogens manipulate host cell cytoskeleton for infection.
• Actin polymerization is crucial for pathogen intracellular motility and spread.
• Shigella flexneri utilizes host actin for its movement.

Purpose of the Study:

• To elucidate the mechanism of Shigella flexneri-induced actin comet tail elongation.
• To investigate the role of Abl family kinases in Shigella intracellular motility.
• To uncover the relationship between Abl kinases, N-WASP, and actin polymerization.

Main Methods:

• Investigated Shigella actin comet tail formation in cells with varying Abl kinase activity.
• Analyzed the phosphorylation of N-WASP by Abl kinases.
• Utilized site-directed mutagenesis of N-WASP phosphorylation sites.
• Assessed the rescue of actin comet tail formation by activated N-WASP.

Main Results:

• Abl kinases are essential for Shigella actin comet tail formation, intracellular motility, and cell-to-cell spread.
• Abl kinases phosphorylate N-WASP, a key host factor for actin polymerization.
• Mutations in Abl phosphorylation sites on N-WASP impair comet tail elongation.
• Activated N-WASP rescues actin comet tail formation in Abl-deficient cells.

Conclusions:

• Abl family kinases regulate Shigella intracellular motility and intercellular dissemination by phosphorylating N-WASP.
• This study identifies a novel role for Abl kinases in pathogen motility regulation.
• The findings provide new insights into host-pathogen interactions and actin dynamics.