Faculty Collaboration Database

Characterization of Rous sarcoma virus intronic sequences that negatively regulate splicing. Virology 1991 Nov;185(1):99-108

Date

11/01/1991

Pubmed ID

1656608

DOI

10.1016/0042-6822(91)90758-4

Scopus ID

2-s2.0-0025953458 (requires institutional sign-in at Scopus site)   74 Citations

Abstract

Retroviruses splice only a fraction of their primary RNA transcripts to subgenomic mRNA. The unspliced RNA is transported to the cytoplasm, where it serves as genomic RNA as well as mRNA for the gag and pol genes. Deletion of sequences from the Rous sarcoma virus gag gene, which is part of the intron of the subgenomic mRNAs, was previously observed to result in an increase in the ratio of spliced to unspliced RNA. These sequences, which we termed a negative regulator of splicing (NRS), can be moved to the intron of a heterologous gene resulting in an accumulation of unspliced RNA in the nucleus. We have used such constructs, assayed by transient expression in chicken embryo fibroblasts, to define the minimal sequences necessary to inhibit splicing. Maximal NRS activity was observed with a 300-nt fragment containing RSV nts 707-1006; two noncontiguous domains within this fragment, one of which contains a polypyrimidine tract, were both found to be essential. The NRS element was active exclusively in the sense orientation in two heterologous introns tested and in both avian and mammalian cells. Position dependence was also observed, with highest activity when the NRS was inserted in the intron near the 5' splice site. The NRS element was also active at an exon position 136 nts upstream of the 5' splice site but not at sites further upstream. In addition, it did not affect the splicing of a downstream intron.

Author List

McNally MT, Gontarek RR, Beemon K

MESH terms used to index this publication - Major topics in bold

Animals
Avian Sarcoma Viruses
Base Sequence
Cells, Cultured
Chick Embryo
DNA, Viral
Genes, gag
Genes, myc
Introns
Molecular Sequence Data
Nucleic Acid Conformation
Polymerase Chain Reaction
RNA Splicing
RNA, Messenger
RNA, Viral
Transcription, Genetic
Transfection