Search results for "Retrovirus"
showing 2 items of 42 documents
Retrovirus infection and aging: Increase in UAG suppressor tRNA expression in aged mice.
1994
Summary The effect of aging on expression of a natural glutamine suppressor tRNA (tRNA Gln(UmUG) ) was studied in different tissues of mice; this tRNA recognizes UAG and inserts glutamine at the site of the termination codon. The level of tRNA Gln(UmUG) was found to be strongly increased in aged mice, compared to newborn and mature animals. An elevated expression of tRNA Gln(UmUG) has also been found in retrovirus-infected cells; in Moloney virus-infected cells the suppressor tRNA allows to read-through the UAG codon within the retroviral protease gene. We suggest that the increase in the level of tRNA Gln(UmUG) may influence retroviral gene expression with age.
The endogenous retroviral insertion in the human complement C4 gene modulates the expression of homologous genes by antisense inhibition
2001
Intron 9 contains the complete endogenous retrovirus HERV-K(C4) as a 6.4-kb insertion in 60% of human C4 genes. The retroviral insertion is in reverse orientation to the C4 coding sequence. Therefore, expression of C4 could lead to the transcription of an antisense RNA, which might protect against exogenous retroviral infections. To test this hypothesis, open reading frames from the HERV sequence were subcloned in sense orientiation into a vector allowing expression of a beta-galactosidase fusion protein. Mouse L cells which had been stably transfected with either the human C4A or C4B gene both carrying the HERV insertion (LC4 cells), and L(Tk-) cells without the C4 gene were transiently tr…