The Coxsackie and adenovirus receptor binds microtubules and plays a role in cell migration

Area of Science:

• Cell Biology
• Molecular Biology
• Neuro-Oncology

Background:

• The Coxsackie and adenovirus receptor (CAR) is an immunoglobulin superfamily cell adhesion molecule known to inhibit tumor cell growth.
• The cytoplasmic domain of CAR is linked to reduced invasion and intracerebral growth of U87 glioma cells.

Purpose of the Study:

• To investigate the molecular mechanisms by which CAR influences glioma cell behavior, specifically focusing on its interaction partners.
• To determine if CAR's cytoplasmic domain interacts with cellular components involved in cell migration.

Main Methods:

• Affinity binding assays to identify CAR interaction partners.
• Co-immunoprecipitation to confirm CAR-tubulin interaction in cells.
• In situ co-localization studies.
• Chemotaxis assays to assess cell migration.
• Treatment with paclitaxel to evaluate the role of microtubules.

Main Results:

• Tubulin was identified as a specific interaction partner for the cytoplasmic domain of CAR.
• CAR and tubulin co-immunoprecipitated and partially co-localized within cells.
• Direct binding of CAR to tubulin heterodimers and microtubules was demonstrated.
• CAR-expressing U87 glioma cells exhibited decreased migration, an effect dependent on CAR's cytoplasmic domain.
• This migratory decrease was abrogated by paclitaxel, indicating a role for microtubules.

Conclusions:

• CAR interacts directly with tubulin and microtubules.
• CAR's interaction with the microtubule cytoskeleton mediates reduced glioma cell migration.
• Targeting the CAR-microtubule interaction could represent a novel therapeutic strategy for gliomas.