Glutathione Peroxidase from Talaromyces marneffei Interacts with Host Cytoskeletal Proteins: Insights from Yeast Two-Hybrid and Molecular Dynamics Simulations.

Talaromyces marneffei is a dimorphic fungal pathogen that can subvert host immune defenses; however, the molecular mechanisms underlying its interactions with host cells remain incompletely understood. Glutathione peroxidase from T. marneffei (TmGpx1) has previously been identified as an antigenic protein that elicits antibody responses in patients with talaromycosis. To elucidate the contribution of TmGpx1 during human-fungal pathogen interaction, the yeast two-hybrid system was performed using TmGpx1 as bait to screen a cDNA library derived from non-induced human macrophage cells. Sixteen candidate host protein partners were identified, with Gene Ontology analysis revealing their predominant association with cytoskeletal and extracellular exosome components. To examine the atomic-level structural interface and dynamic behavior of protein-protein interactions, we employed molecular dynamics (MD) simulations to investigate the interaction between TmGpx1 and FKBP15, a human protein involved in early endosomal regulation and associated with both microtubule and actin filaments. Per-residue decomposition analysis using gmx_MMPBSA identified LEU124 of TmGpx1 and ARG616 of FKBP15 as critical residues mediating the protein-protein interaction. Notably, the key residues of TmGpx1 are located toward the N-terminus and are mapped outside of the catalytic active site, suggesting that the interaction of TmGpx1 with host cytoskeletal components may occur independently of its enzymatic antioxidant activity. Overall, our findings provide novel insights into the repertoire of host cytoskeletal and membrane trafficking proteins that may be targeted for remodeling during T. marneffei infection. Elucidation of these molecular interactions advances our understanding of host-pathogen dynamics and opens new avenues for the development of targeted diagnostics and therapeutic strategies against talaromycosis.