Abstract
Infection by human papillomavirus type 16 (HPV-16) has been linked to cervical cancer. The transcription of viral genes in HPV-16 is partially controlled by a number of cellular transcription factors. We have previously identified a novel cellular transcription factor, PEF- 1, from its ability to interact with the long control region (LCR) of HPV-16. This factor has a molecular mass of about 110 kDa and binds to a GC-rich sequence in the section of the LCR responsible for cell type- specific transcription from viral DNA. The factor Sp1 has similar properties and also interacts with the HPV-16 LCR. We show that PEF-1 and Sp1 are distinct transcription factors: they recognize different DNA sequences, have different electrophoretic mobilities and different glycosylation patterns. Sp1 is O-glycosylated while PEF-1 appears to have a novel type of glycosylation, as shown by the interaction with pokeweed lectin and by the inhibition of this interaction by tunicamycin.