title: Expression and functional properties of proteins encoded in the x-II ORF of HTLV-I.
abstract: With the aim of identifying viral proteins that contribute to the distinctive properties of HTLV-I biology and pathogenicity, several laboratories have investigated the coding potential of the X region of the genome, which includes five partially overlapping open reading frames (ORFs). We and others have shown that, in addition to the essential regulatory proteins Rex and Tax, a number of accessory proteins encoded in the X region can be produced by alternative splicing and multicistronic translation. One X region ORF, termed X-II, produces two protein isoforms named Tof/p30II and p13II, which are expressed from a doubly- and singly-spliced mRNA, respectively. Initial functional analyses demonstrated that Tof/p30II is a nucleolar/nuclear protein that possesses a region capable of binding to RNA, and p13II is a mitochondrial protein that alters the morphology and function of this organelle. Together with data from other laboratories demonstrating the production of antibodies and CTL against x-II ORF products in HTLV-I infected subjects and the requirement of this ORF for efficient viral replication in vivo, these findings suggest that further characterization of Tof/p30II and p13II will yield insight into remaining undefined aspects of HTLV-I pathogenicity and replication.
authors.affiliation: Department of Oncology and Surgical Sciences, University of Padva, Via Gattamelata 64, 35128, Padua, Italy.
authors.forename: D M
authors.initials: DM
authors.lastname: D'Agostino
authors.forename: L
authors.initials: L
authors.lastname: Zotti
authors.forename: T
authors.initials: T
authors.lastname: Ferro
authors.forename: I
authors.initials: I
authors.lastname: Cavallori
authors.forename: M
authors.initials: M
authors.lastname: Silic-Benussi
authors.forename: L
authors.initials: L
authors.lastname: Chieco-Bianchi
authors.forename: V
authors.initials: V
authors.lastname: Ciminale
mesh_terms: D000595:Amino Acid Sequence; D015870:Gene Expression; D016355:Genes, pX / Q000502:physiology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D012191:Retroviridae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012191:Retroviridae Proteins; C072814:tof protein, Human T-lymphotropic virus 1