Myosin Vc, a member of the actin motor family associated with Rab8, is involved in the release of DV2 from HepG2 cells.

OBJECTIVE The pathogenesis of the dengue virus (DV) infection has not been well defined. We have reported that actin and Rab8 are involved in DV2 infection. Myosin Vc (Myo5c) is a novel member of the class V myosins and regulates the actin-mediated membrane trafficking associated with Rab8. In this study, the involvement of Myo5c in the release of DV2 was investigated in HpeG2 cells. METHODS Distributions of actin, Myo5c, DV2 and Rab8 were revealed by fluorescent staining. HepG2(Myo5c-tail) cells expressing a dominant-negative mutant of Myo5c were constructed by transfection and were assessed by Western blotting. The viral titers were detected by plaque assay, and the expression of Rab8 was analyzed by flow cytometry. RESULTS DV2 infection altered the distribution pattern of Myo5c, which might be associated with the depolymerization of actin, though colocalization rates of Myo5c with DV2 or actin were low. Furthermore, the release of DV2, but not the intracellular viral production, was reduced from HepG2(Myo5c-tail) cells. Moreover, Myo5c colocalized with Rab8 and an increase of Rab8 was associated with the decrease of the viral release caused by the Myo5c tail. CONCLUSIONS Our data suggest that Myo5c associated with Rab8 is involved in the release of DV2 from HepG2 cells.