Sl. Chen et al., E5 PROTEINS OF HUMAN PAPILLOMAVIRUS TYPE-11 AND TYPE-16 TRANSACTIVATETHE C-FOS PROMOTER THROUGH THE NF1 BINDING-ELEMENT, Journal of virology, 70(12), 1996, pp. 8558-8563
Human papillomavirus type II (HPV-11) and HPV-16 contain an E5 gene th
at can induce c-Sos gene expression in mouse fibroblasts. This study i
nvestigated the human c-fos promoter characteristics by mapping the c-
Sos promoter sequence with several deletion and point mutants that con
fer responsiveness to E5 of HPV-11 or HPV-16. The mutant studies show
that NF1 binding sequences within the c=fos promoter were crucial for
the induction of the c-fos gene by E5, and the gel shift assay study s
uggested that E5 of both HPV-11 and HPV-16 is associated, perhaps indi
rectly with this NF1 element in the transactivation of the human c-Sos
promoter, Using an inducible system, me demonstrate that increased in
duction of the HPV-11 E5 gene in cells led to increased transactivatio
n of the NF1 element. In addition, the transactivating activity of a s
eries of HPV-11 E5 mutants on the NF1 element had a strong correlation
with their respective transforming activities.