Molecular and biological properties of c-mil transducing retroviruses generated during passage of Rous-associated virus type 1 in chicken neuroretina cells.
AUTOR(ES)
Eychène, A
RESUMO
IC1, IC2, and IC3 are novel c-mil transducing retroviruses generated during serial passaging of Rous-associated virus type 1 (RAV-1) in chicken embryo neuroretina cells. They were isolated by their ability to induce proliferation of these nondividing cells. IC2 and IC3 were generated during early passages of RAV-1 in neuroretina cells, whereas IC1 was isolated after six consecutive passages of virus supernatants. We sequenced the transduced genes and the mil-RAV-1 junctions of the three viruses. The 5' RAV-1-mil junction of IC2 and IC3 was formed by a splicing process between the RAV-1 leader sequence and exon 8 of the c-mil gene. The 5' end of IC1 resulted from homologous recombination between gag and mil sequences. Reconstitution experiments showed that serial passaging of IC2 in neuroretina cells also led to the formation of a gag-mil-containing retrovirus. Therefore, constitution of a U5-leader-delta c-mil-delta RAV-1-U3 virus represents early steps in c-mil transduction by RAV-1. This virus further recombined with RAV-1 to generate a gag-mil-containing virus. The three IC viruses transduced the serine/threonine kinase domain of the cellular gene. Hence, amino-terminal truncation is sufficient to activate the mitogenic property of c-mil. Comparison of the transforming properties of IC2 and IC1 showed that the transduced mil gene, expressed as a unique protein independent of gag sequences, was weakly transforming in avian cells. Acquisition of gag sequences by IC1 not only increased the rate of virus replication but also enhanced the transforming capacity of the virus.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=249095Documentos Relacionados
- Common mechanism of retrovirus activation and transduction of c-mil and c-Rmil in chicken neuroretina cells infected with Rous-associated virus type 1.
- Integration of Rous-associated virus type O provirus in susceptible chicken cells.
- Activation and transduction of c-mil sequences in chicken neuroretina cells induced to proliferate by infection with avian lymphomatosis virus.
- Occurrence of alternatively spliced leader-delta onc-poly(A) transcripts in chicken neuroretina cells infected with Rous-associated virus type 1: implication in transduction of the c-mil/c-raf and c-Rmil/B-raf oncogenes.
- A novel oncogene related to c-mil is transduced in chicken neuroretina cells induced to proliferate by infection with an avian lymphomatosis virus.