Myosin-X facilitates Shigella-induced membrane protrusions and cell-to-cell spread

Area of Science:

• Cell Biology
• Microbiology
• Molecular Biology

Background:

• Intracellular pathogens like Shigella flexneri utilize host cell machinery to spread.
• Membrane protrusions are critical for cell-to-cell dissemination of Shigella.
• The role of specific host factors in mediating this process remains incompletely understood.

Purpose of the Study:

• To investigate the role of myosin-X (Myo10) in Shigella-induced membrane protrusion formation.
• To elucidate the mechanism by which Myo10 influences bacterial spread.
• To determine the functional domains of Myo10 involved in this process.

Main Methods:

• Immunogold electron microscopy of infected HeLa cells.
• Time-lapse video microscopy of Myo10-GFP constructs.
• RNA interference (RNAi) for Myo10 knock-down.
• Expression of Myo10 domain constructs in Cos7 cells.

Main Results:

• Myo10 localizes to Shigella within membrane protrusions and co-localizes with bacterial spread.
• Myo10 knock-down reduces protrusion length and impairs bacterial plaque formation.
• Overexpression of full-length Myo10 significantly increases protrusion length, dependent on its head and PH domains.
• Specific domains of Myo10 interact with actin filaments and host cell membranes.

Conclusions:

• Myosin-X (Myo10) is a key host factor that enhances Shigella-induced membrane protrusion formation.
• Myo10 generates force for protrusion elongation by interacting with actin and the host cell membrane.
• Myo10 plays a significant role in the cell-to-cell spread of Shigella and Listeria.