It has been reported that SV40-transformed V 11 F 1 clone 1 subclone 7 rat cells (subclone 7) produce a super T antigen of 115,000 M .This super T antigen is entirely SV40 coded and is synthesized by traRslation of an elongated form of SV40 early mRNA (May, E., Kress, M., DayaGrosjean, L., Monier, R. and May, P. (1981) J. Virol., 37,[24][25][26][27][28][29][30][31][32][33][34][35] Two recombinant cosmids were constructed by insertion of the 5 Kb and 10 Kb fragments, respectively, into cosmid pHC 79. Using restriction map analysis and nucleotide sequencing, we showed that the 5 Kb fragment actually contained the complete sequence of a gene encoding super T antigen.As compared to the normal SV40 early gene, the sequence of super T gene showed the following rearrangements: (i) The segment between nucleotides 4116 -3544 was duplicated in a direct order and (ii) these two copies of 573 nucleotide sequence were separated by a 93 nucleotide tract which was a nearly perfect inverted repeat of the segment located between nucleotides 4868 and 4776 (nucleotide numbering used here = Weissmann number + 17).
INTlR)DUCIONMultiple species of T antigens with molecular weight distinct from normal sized large T antigen can be identified in a variety of SV40 transformed rat and mouse cell lines. Species of T antigen with a molecular weight considerably larger than that of normal-sized large T antigen are widespread in SV40-transformed rat or mouse cells and are referred to as super T antigen (1, 2, 3, 4).As already reported (5) SV40 transformed rat cell line V 11 F 1 clone 1 subclone 7 produces a single species of super T antigen of 115,000Mr in the absence of detectable trace of large T antigen (86,000 Mr). We have previously shown that this super T antigen (super T) is an elongated form of large T antigen, which contains a duplication of that part of large ©) IRL Prm Umited, 1 Falconberg Court, London W1V 5FG, U.K.4111