Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human papillomavirus (HPV) is frequently associated with cervical carcinoma and derived cell lines. In primary tissues of the carcinoma, the viral genome may be present in episomal or integrated configuration. In cell lines, however, only integrated HPV sequences have been reported. In this article, we describe the presence of episomal type 16 HPV (HPV16), demonstrated by electron microscopy and two-dimensional agarose gel electrophoresis, in a cervical carcinoma cell line, CC7T/VGH, established in 1980 in Taiwan. In CC7T/VGH, the HPV16 sequences are transcriptionally active, and at least three major HPV16 RNA species were detected in Northern blots. Results from restriction enzyme and S1 nuclease analysis suggest a composition of oligomeric HPV16 molecules in dimeric repeats. In addition, the HPV16 oligomers exist as catenated molecules of interlocking rings instead of concatemers. A monomeric copy of the HPV16 episome was cloned from a Hirt supernatant of CC7T/VGH by using a plasmid vector. Mapping and partial sequencing studies revealed an internal deletion of 163 base pairs within the L1 open reading frame. However, insertion of an A.C nucleotide pair at the deletion junction restored the otherwise frame-shifted L1 open reading frame. Two base transitions were also found within the E7 and the E1 open reading frames. Our findings suggest the need for closer examination for HPV episomal catenation in other cervical carcinoma cell lines as well as in primary carcinoma tissues of the uterine cervix and the anogenital tract. With CC7T/VGH, a way is now available for studies of many important aspects of the biology of HPV such as replication and gene expression of the extrachromosomal viral genome.
 ...
PMID:Presence of catenated human papillomavirus type 16 episomes in a cervical carcinoma cell line. 253 4

The genomes of two new genital human papillomavirus (HPV) types, tentatively named HPVs 39 and 42, have been cloned from biopsy specimens of penile Bowenoid papules and vulvar papillomas, respectively. Blot hybridization experiments, performed under stringent conditions (Tm -10 degrees), have revealed no cross-hybridization between the DNAs of HPVs 39 and 42, and between these DNAs and those of other genital and cutaneous HPVs. A significant cross-hybridization has been observed between the DNA of HPV42 and that of HPV32, the latter being associated with oral focal epithelial hyperplasia. The fraction of HPV32 and HPV42 hybrid molecules resistant to nuclease S1 treatment after hybridization in liquid phase at saturation has been evaluated to 20%, supporting the view that these HPVs constitute distinct types. In addition to HPV42 DNA, a 6.8-kb BamHI fragment, cross-hybridizing with HPV39 DNA, has been cloned from the vulvar papilloma DNA preparation. The cross-hybridization has been evaluated to 16%, pointing to the existence of an additional HPV39-related type. Electron microscope analysis of heteroduplex molecules formed between HPV32 and HPV42 DNAs showed paired regions over about 60 and 87% of their genome lenghts under stringent (Tm -18 degrees) and nonstringent (Tm -42 degrees) conditions, respectively. The 6.8-kb HPV DNA and HPV39 DNA formed paired regions over about 63 and 95% of the 6.8-kb fragment length at Tm -18 degrees and Tm -26 degrees, respectively. These data point to greater DNA sequence homologies than anticipated from the percentages of nuclease S1 resistance. Heteroduplex mapping has allowed the alignment of the physical maps of HPV39 and 42 DNAs and of the 6.8-kb HPV DNA with the map of the open reading frames of the HPV16 genome. So far, HPV42 has been detected only in benign genital lesions showing usually no cell atypia. HPV39 has been detected in a few cases of intraepithelial neoplasias and invasive carcinomas of the uterine cervix. The viral DNA sequences have been found integrated into the cell genome in all four HPV39-associated cervical cancers of our series. It seems most likely that HPV42 belongs to the low-risk group of genital HPVs, while HPV39 represents a potentially oncogenic genital HPV type.
 ...
PMID:Plurality of genital human papillomaviruses: characterization of two new types with distinct biological properties. 282 11