Simian virus 40 large T antigen targets the microtubule-stabilizing protein TACC2

Area of Science:

• Virology
• Cell Biology
• Molecular Oncology

Background:

• Polyomavirus large T antigens are known to target key cellular regulators like p53 and RB family proteins.
• Understanding T-antigen-induced cell transformation requires identifying all interacting proteins, as novel targets may be involved.
• Emerging polyomaviruses are linked to severe human diseases, including aggressive skin cancers.

Purpose of the Study:

• To investigate novel cellular targets of simian virus 40 (SV40) large T antigen.
• To elucidate the role of TACC2 in SV40 T-antigen-mediated cellular dysfunction and transformation.

Main Methods:

• Co-immunoprecipitation assays to detect protein-protein interactions.
• Immunofluorescence microscopy to visualize microtubule and spindle organization.
• Analysis of mitotic progression and chromosome segregation in SV40-infected cells.

Main Results:

• SV40 large T antigen directly binds to the transforming acidic coiled-coil-containing protein 2 (TACC2).
• T-antigen interaction with TACC2 leads to microtubule dysfunction, disorganized mitotic spindles, and chromosome missegregation.
• Mitotic defects are dependent on T-antigen's interaction with TACC2, as N-terminal deletion reduces binding and TACC2 overexpression mitigates microtubule destabilization.

Conclusions:

• TACC2 is identified as a novel cellular target of SV40 large T antigen.
• Disruption of microtubule regulation and chromosomal inheritance by T-antigen via TACC2 may be critical in initiating cell transformation.
• Targeting TACC2 represents a potential mechanism by which SV40 contributes to cellular pathogenesis.