A role for alpha-and beta-catenins in bacterial uptake

Area of Science:

• Microbiology and Cell Biology

Background:

• Internalin protein interaction with E-cadherin facilitates Listeria monocytogenes invasion into human epithelial cells.
• Bacterial entry necessitates actin cytoskeleton rearrangements.

Purpose of the Study:

• To elucidate the specific domains of E-cadherin involved in Listeria monocytogenes adherence and entry.
• To investigate the role of catenins and the actin cytoskeleton in the bacterial invasion process.

Main Methods:

• Utilized stably transfected cell lines expressing various E-cadherin variants.
• Generated and tested a chimeric molecule linking E-cadherin ectodomain to alpha-catenin's actin-binding site.
• Analyzed the colocalization of E-cadherin, alpha-catenin, beta-catenin, and F-actin at the bacterial entry site.

Main Results:

• The ectodomain of E-cadherin is sufficient for bacterial adherence.
• The intracytoplasmic domain, specifically the beta-catenin binding region, is crucial for bacterial entry.
• A chimera molecule demonstrated that the actin-binding site of alpha-catenin can mediate bacterial entry.
• E-cadherin, alpha-catenin, beta-catenin, and F-actin colocalize during bacterial invasion.

Conclusions:

• E-cadherin acts as a crucial mediator for Listeria monocytogenes entry.
• The E-cadherin-mediated invasion pathway involves beta-catenin and alpha-catenin, leading to actin polymerization and membrane extensions for bacterial uptake.