Molecular cloning, analysis, and chromosomal localization of a mouse genomic sequence related to the human papillomavirus type 18 E5 region

Abstract

The E5 open reading frame (ORF) from bovine papillomavirus type 1 (BPV 1) as well as the E5 ORFs from human papillomaviruses (HPV) type 6 and type 16 have been reported to transform immortalized rodent cells. In an analysis of murine and human tumors for the presence of putative papillomavirus-related sequences, we cloned amplified cellular sequences from the mouse cell line Eb that cross-hybridized with the E5 ORF of HPV 18. A 2.1-kb fragment termed HC1 was sequenced. In normal murine cells, it was present as a single-copy genomic sequence located on chromosome 8. A region of 213 nucleotides corresponded to the E5 gene (HC1 E5), based on the best alignments and on the presence of direct and inverted repeats bearing a central sequence motif. These structural elements are also present in the HPV 18 E5 ORF. HC1 E5 contained an ORF that was transcribed bidirectionally. The transcription in the E5 direction was enhanced in RNA obtained from organs and tumors from carcinogen-treated animals and C127 cells. The polypeptide deduced from the sequence was related to E5 proteins from genital papillomaviruses, to the putative product of the Q300 mouse gene, and to several viral and human growth factors. The data suggest that there may be several cellular counterparts to the viral E5 proteins.

Detection of E5 oncoprotein in human papillomavirus type 16-positive cervical scrapes using antibodies raised to synthetic peptides

“…Although E5 protein was detected in a sample that was both HPV-16-and HPV-18-positive, PE-6 antiserum was considered to be specific for HPV-16 E5 because of the low amino acid sequence homology (31-3%) between HPV-16 E5 and HPV-18 E5. It was considered most unlikely that the antiserum was reacting with a cellular E5 homologue, as identified in mice by Kahn et al (1992), as no protein was identified in the HPV-negative sample or indeed in four of the HPV-16-positive samples. The detected protein was twice the expected M r of HPV-16 E5.…”

Promoter Activity of Sequences Located Upstream of the Human Papillomavirus Types 16 and 18 Late Regions

“…These fndings raised the possibility that the DNA region preceding the late ORFs, designated in the following as late upstream region (LUR), has a function for the differentiationdependent regulation of late gene expression. This possibility is supported by sequence analyses demonstrating that transcribed HPV ES-like sequences from mice and humans (Wagner et al, 1991;Kahn et al, 1992;Geisen et al, 1995) show similarities not only to ES, but also to upstream regulatory regions of genes known to be expressed in a tissue-or differentiation-specific manner (Kahn et al, 1992;Geisen, 1993;Geisen et al, 1995). Furthermore, sequences located at the 5' end of the HPV-16 and HPV-18 URRs have a pronounced similarity to sequences at the 3' end of the E50RF and the intervening sequence between the E5 and L20RFs of HPV-16 and HPV-18 (T. Kahn, unpublished results).…”

Cloning and characterization of a novel caprine genomic repetitive element that hybridizes with papillomavirus DNA

“…A cellular homologue of the papillomavirus E5 oncogene was detected as a single copy sequence in the murine genome by hybridization with a human papillomavirus type 18 (HPV 18) genomic probe [6], and a 94 bp sequence in the human genome was related to a sequence in the LCR of HPV 6 [5]. In addition, unidentified cellular sequences in skin tumours and normal tissue of mice [8,9] and sheep [10] were detected with variable frequency by DNA hybridization using different animal and human papillomavirus DNA probes at reduced stringency.…”