Protein recognition sites in polyomavirus enhancer: formation of a novel site for NF-1 factor in an enhancer mutant and characterization of a site in the enhancer D domain.
Polyomavirus mutants selected for modified host range exhibit DNA sequence alterations in the regulatory region, which consist mainly of duplications and/or deletions. Single base pair mutations have also been observed, which create or abolish DNA sequence motifs recognized by DNA-binding regulatory factors. The present work deals with the molecular characterization of a Polyoma mutant (PyNB11/1), selected for its high efficiency of growth in neuroblastoma cells. The enhancer region of PyNB11/1 displays a 91 bp tandem duplication harbouring a novel DNA sequence motif created at the boundary of the duplicated fragment. This motif is absent in the wild-type enhancer and is specifically recognized by a nuclear factor that belongs to the NF-1 family of transcription factors. We also report the characterization of an as yet unidentified DNA sequence motif in the D domain of the viral enhancer, that represents the binding site for a nuclear factor that is ubiquitous and comparably abundant in several murine cell types.
Caruso
M
M
Dipartimento di Biopatologia Umana, Università La Sapienza, Roma, Italy.
Iacobini
C
C
Passananti
C
C
Felsani
A
A
Amati
P
P
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D003850:Deoxyribonuclease I; D004742:Enhancer Elements, Genetic; D005809:Genes, Regulator; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009447:Neuroblastoma; D015345:Oligonucleotide Probes; D011120:Polyomavirus / Q000235:genetics*; D015183:Restriction Mapping; D014157:Transcription Factors / Q000378:metabolism*
D004279:DNA, Viral; D015345:Oligonucleotide Probes; D014157:Transcription Factors; D003850:Deoxyribonuclease I