Point mutations in SP1 motifs in the upstream regulatory region of human papillomavirus type 18 isolates from cervical cancers increase promoter activity.
Evidence of the functional significance of two naturally occurring mutations at nt 40 or 41 in the Sp1 motif in the promoter proximal segment of the upstream regulatory region (URR) of human papillomavirus (HPV) type 18 is presented. In electrophoretic mobility shift assays, Sp1 protein bound more efficiently to the Sp1 mutant motifs than to the prototype; while in both HeLa and HT3 cells, luciferase activity controlled by the mutant URRs was upregulated 2- and 3-fold, or 4- and 6-fold, in comparison with the prototype URR or HeLa cell-derived URR respectively. The HeLa URR represents a more appropriate baseline for promoter activity, containing a series of point mutations representative of most HPV-18 cancer isolates, including one in the Yin Yang 1 (YY1) site at the P105 promoter. The effect of the Sp1 mutations was found to be largely maintained in the context of the HeLa URR containing the prototype YY1 site.
Rose
B
B
Department of Infectious Diseases, Blackburn Building (DO6), The University of Sydney, NSW, Australia. b_rose@infdis.usyd.edu.au
Steger
G
G
Dong
X P
XP
Thompson
C
C
Cossart
Y
Y
Tattersall
M
M
Pfister
H
H
D000409:Alanine / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D005260:Female; D005998:Glycine / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D027383:Papillomaviridae / Q000235:genetics* / Q000378:metabolism*; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D013912:Threonine / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D002583:Uterine Cervical Neoplasms / Q000821:virology; D050986:YY1 Transcription Factor
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; D013912:Threonine; D000409:Alanine; D005998:Glycine