1.A.98 The Human T-Lymphotropic Virus 1 P13 protein (HTLV1-P13) Family

Human T-cell leukemia virus type-1 (HTLV-1) encodes a mitochondrial protein named p13. p13 mediates an inward K⁺ current in isolated mitochondria that leads to mitochondrial swelling, depolarization, increased respiratory chain activity and reactive oxygen species (ROS) production. These effects trigger the opening of the permeability transition pore and are dependent on the presence of K⁺ and on the amphipathic α-helical domain of p13. In the context of cells, p13 acts as a sensitizer to selected apoptotic stimuli. It shares some structural and functional analogies with viroporins, a class of small integral membrane proteins that form pores and alter membrane permeability (Silic-Benussi et al. 2010). p13 is essential for the establishment and maintenance of HTLV-1 infection in vivo (Edwards et al. 2011).