Viruses (Jun 2011)

Orf-I and Orf-II-Encoded Proteins in HTLV-1 Infection and Persistence

  • Genoveffa Franchini,
  • Cynthia A. Pise-Masison,
  • Cody Buchmann,
  • Maria Fernanda de Castro-Amarante,
  • Heather Gold,
  • Claudio Fenizia,
  • Dustin Edwards

DOI
https://doi.org/10.3390/v3060861
Journal volume & issue
Vol. 3, no. 6
pp. 861 – 885

Abstract

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The 3' end of the human T-cell leukemia/lymphoma virus type-1 (HTLV-1) genome contains four overlapping open reading frames (ORF) that encode regulatory proteins. Here, we review current knowledge of HTLV-1 orf-I and orf-II protein products. Singly spliced mRNA from orf-I encodes p12, which can be proteolytically cleaved to generate p8, while differential splicing of mRNA from orf-II results in production of p13 and p30. These proteins have been demonstrated to modulate transcription, apoptosis, host cell activation and proliferation, virus infectivity and transmission, and host immune responses. Though these proteins are not essential for virus replication in vitro, p8, p12, p13, and p30 have an important role in the establishment and maintenance of HTLV-1 infection in vivo.

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