Expression of the antiviral protein MxA in cells transiently perturbs endocytosis.
MxA is an interferon-induced antiviral protein. Viral replication relies on the trafficking machinery of the host cell. Overexpression of MxA was found to perturb trafficking of internalized transferrin resulting in its accumulation in cells. Interestingly, this perturbation of endocytic trafficking was transient--with a maximal effect being seen 5-6 h after transfection. By 12 h after transfection the perturbation of endocytosis was seen to have subsided although MxA protein levels remained elevated even 24 h after transfection. The accumulation of transferrin is due to a block in transferrin recycling. It is further shown that MxA can physically associate with the endocytic protein dynamin, possibly accounting for the observed effect of MxA expression on transferrin endocytosis. These results uncover a hitherto unknown aspect of MxA action on trafficking processes within cells.
Jatiani
Shashidhar S
SS
Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India.
Mittal
Rohit
R
D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004705:Endocytosis / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D064547:Myxovirus Resistance Proteins; D021381:Protein Transport / Q000502:physiology; D013997:Time Factors; D014018:Tissue Distribution
D000998:Antiviral Agents; D064547:Myxovirus Resistance Proteins; D019204:GTP-Binding Proteins