Expression and functional properties of proteins encoded in the x-II ORF of HTLV-I.
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.
D'Agostino
D M
DM
Department of Oncology and Surgical Sciences, University of Padva, Via Gattamelata 64, 35128, Padua, Italy.
Zotti
L
L
Ferro
T
T
Cavallori
I
I
Silic-Benussi
M
M
Chieco-Bianchi
L
L
Ciminale
V
V
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
D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012191:Retroviridae Proteins; C072814:tof protein, Human T-lymphotropic virus 1