SV40 large T shares an antigenic determinant with a cellular protein of molecular weight 68,000

Abstract

The large T protein coded by the early region of simian virus 40 (SV40) is involved in the induction and maintenance of cell transformation. It is not clear which properties of T are important in causing the transformation, since the protein is multifunctional. To clarify the action of T proteins in transformation, we have prepared several monoclonal antibodies directed against different regions of the T molecule. One of these antibodies, DL 3C4, recognizes an antigenic determinant on T that is also present on a host cell protein of molecular weight 68,000. This cross-reactive 68K protein is located within the nucleus of all mammalian cell types examined and has a characteristic granular distribution as shown by immunofluorescence. The antigenic determinant recognized by DL 3C4 is resistant to denaturation. Studies on Adeno-SV40 hybrid viruses show that the antigenic site on T is coded for by sequences located between 0.44 and 0.29 on the SV40 map.

A Drosophila fragile X protein interacts with components of RNAi and ribosomal proteins

“…The p68 RNA helicase was first identified by cross-reaction with a monoclonal antibody that was originally raised against SV40 large T antigen two decades ago (Lane and Hoeffler 1980). The helicase plays important roles in cell proliferation and organ maturation (Iggo et al 1991;Stevenson et al 1998) and belongs to a large family of highly evolutionarily conserved proteins, the so-called DEAD-box family of putative ATPases and helicases (for review, see de la Cruz et al 1999).…”

p68 DEAD Box RNA Helicase Expression in Keratinocytes

“…Within the repair process, a controlled but strong proliferation of wound margin keratinocytes drives the re-epithelialization of the wounded area. Here we demonstrate that p68 is regulated during skin repair and that p68 is functionally connected to keratinocyte proliferation and vascular endothelial growth factor (VEGF) 1 expression in the cells.…”

“…The story of RNA helicases started in 1980, as a yet unknown 68-kDa-sized protein was identified by its strong cross-reactivity with an antibody that has been raised against the simian virus 40 large T antigen (1). A few years later, the cDNA was cloned, and subsequent sequence determination revealed a 68-kDa protein that was characterized by a marked homology to the eucaryotic initiation factor-4A (2).…”

Viruses and Autoimmune Diseases

“…Observations at that time proved that monoclonal antibodies directed against a specific viral protein also cross-reacted with host self proteins [17][18][19]. For example, cross-reactivity was clear between measles virus phosphoprotein (72 kD molecular weight) and cytoskeletal keratin (54 kD molecular weight), and between herpes simplex virus glycoprotein (140 kD) and another epitope on keratin [18].…”