Molecular cloning of cDNA encoding gp68 of adult T-cell leukaemia-associated antigen: evidence for expression of the pX IV region of human T-cell leukaemia virus.

A 2.3 kb cDNA was cloned from human T-cell leukaemia virus [HTLV(MT-2)] virion RNA using a vector system, as plasmid pHTLV 707. The restriction endonuclease map of pHTLV 707 revealed that the insert contained the 5' half of the env gene and a portion of the pX region of HTLV, corresponding to the subgenomic RNA derived from 32S defective HTLV. Nucleotide sequence analysis of pHTLV 707 indicated that the clone contained an open reading frame for a 60K mol. wt. protein including the upstream and entire pX IV region. A rabbit antibody raised against a synthetic decapeptide deduced from the nucleotide sequence at the carboxyl terminus of the pX IV region immunoprecipitated gp68, and also 80K and 40K proteins.