Human T-cell leukemia virus minus strand transcription in infected T-cells.

The plus strand of the Human T-cell Leukemia Virus RNA genome encodes proteins critical for infectivity, replication, and transformation. Thus far, gene products encoded on the minus strand of the HTLV-I provirus have not been found. We have identified several open reading frames, located between transcription start and poly (A) signal sequences on the minus strand of HTLV-I. The 3' terminus of HTLV-I was shown to promote test gene expression in either orientation. RNA blots probed with single stranded RNA complementary to the predicted transcribed region revealed 2.5 and 2.9 kilobase minus strand RNAs in HTLV-I infected T-cells but not in an uninfected control. The effect of mutations on minus strand gene products should also be considered when studying human retroviral protein function by mutational analysis.