When simian virus 40 (SV4O) is serially passaged at high multiplicity, a heterogeneous collection of naturally arising variants is generated. Some of these variant viruses become very abundant in later serial passages presumably due to their enhanced replication efficiency. Previous studies have shown that these abundant variants contain multiple copies of the SV40 replication origin, frequently as inverted repeats and in association with inserts of host DNA. These evolutionarily-selected origin regions will be cloned into a bacterial plasmid and then transfected into monkey cells constitutively producing T antigen (COS cells) in order to quantitate the effects of duplicated sequences, inverted repetitions, and insertions of host DNA on the replication efficiency of the SV40 origin region. In addition, the evolutionarily-optimized sequences will be further modified by in vitro mutagenesis in order to precisely define those features of the nucleotide sequence which affect replication. Clones from a monkey genomic library which hybridize to the variant-selected host DNA segments will also be analysed for functional activity. The proposed studies constitute a unique approach to understanding the functional aspects of a replication sequence and to understanding the regulation of replication. Both types of understanding have important implications for understanding oncogenesis and viral-host interactions.
| He, Xin; Janeway Jr, Charles A; Levine, Matthew et al. (2002) Dual receptor T cells extend the immune repertoire for foreign antigens. Nat Immunol 3:127-34 |
| Szymanski, P; Woodworth, M (1990) A 69-base-pair monkey DNA sequence enhances simian virus 40 replication and transcription through multiple motifs. J Virol 64:1360-5 |
| Lee-Chen, G J; Woodworth-Gutai, M (1986) Simian virus 40 DNA replication: functional organization of regulatory elements. Mol Cell Biol 6:3086-93 |
| Lee-Chen, G J; Woodworth-Gutai, M (1986) Evolutionarily selected replication origins: functional aspects and structural organization. Mol Cell Biol 6:3077-85 |
