The chloramphenicol-acetyl-transferase (CAT) expression system has been utilized to study the ability of the polyomavirus (Py) early proteins, the 100K large T, the 55K middle T and 22K small T-antigens, to activate a variety of eukaryotic promoters (the SV40 early, the alpha 2(1) collagen, the rabbit beta-globin, the polyomavirus early and the H-2 class I) in both transient and stable expressi...

Little is known about viruses associated with Antarctic animals, although they are probably widespread. We recovered a novel polyomavirus from Adélie penguin (Pygoscelis adeliae) faecal matter sampled in a subcolony at Cape Royds, Ross Island, Antarctica. The 4988 nt Adélie penguin polyomavirus (AdPyV) has a typical polyomavirus genome organization with three ORFs that encoded capsid proteins o...

By using the polymerase chain reaction (PCR) technique, a technique more sensitive than Southern analysis, which allows detection of polyomavirus DNA only in newborn and nude adult mice, it has now been possible to monitor the persistence pattern of polyomavirus DNA after infection of normal adult CBA mice for the first time. Viral signs appeared gradually, showing variations in time course and...

Merkel cell polyomavirus (MCV) is the etiological agent of Merkel cell carcinoma (MCC), a rare and highly lethal human skin cancer. A natural component of skin flora, MCV becomes tumorigenic only after integration into the host DNA together with specific mutations to the viral genome. Research on MCV large T (LT) and small T (sT) antigens, the only viral products expressed in MCC, shows that th...

While studying the virome of the skin surface of a patient with a Merkel cell carcinoma (MCC) by using unbiased, high-throughput sequencing, we identified a human polyomavirus nearly identical to human polyomavirus 9, a virus recently reported in blood and urine of renal transplantion patients and closely related to the African green monkey lymphotropic polyomavirus. Specific PCR analysis furth...

The nuclear envelope is one of the chief obstacles to the translocation of macromolecules that are larger than the diameter of nuclear pores. Heterochromatin protein 1 (HP1) bound to the lamin B receptor (LBR) is thought to contribute to reassembly of the nuclear envelope after cell division. Human polyomavirus agnoprotein (Agno) has been shown to bind to HP1alpha and to induce its dissociation...

To map the DNA-binding domain of polyomavirus large T antigen, we constructed a set of plasmids coding for unidirectional carboxy- or amino-terminal deletion mutations in the large T antigen. Analysis of origin-specific DNA binding by mutant proteins expressed in Cos-1 cells revealed that the C-terminal boundary of the DNA-binding domain is at or near Glu-398. Fusion proteins of large T antigen...

The PCAF and GCN5 acetyltransferases, but not p300 or CBP, stimulate DNA replication when tethered near the polyomavirus origin. Replication stimulation by PCAF and GCN5 is blocked by mutational inactivation of their acetyltransferase domains but not by deletion of sequences that bind p300 or CBP. Acetylation of histones near the polyomavirus origin assembled into chromatin in vivo is not detec...

Merkel cell polyomavirus (MCPyV) is the first polyomavirus clearly associated with a human cancer, i.e. the Merkel cell carcinoma (MCC). Polyomaviruses are small naked DNA viruses that induce a robust polyclonal antibody response against the major capsid protein (VP1). However, the polyomavirus VP1 capsid protein epitopes have not been identified to date. The aim of this study was to identify t...