M2 pyruvate kinase enhances HIV-1 transcription from its long terminal repeat

Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and M2PK on the transcription of human immunodeficiency virus type 1(HIV-1)was tested.The results indicated that M2PK could enhance HIV-1 transcription from its long terminal repeat(LTR)promoter,while RPK did not have such an effect.Specific down-regulation of M2PK could inhibit HIV-1 transcription from its LTR region.Furthermore,it was found that the C terminal region of M2PK is responsible for this effect.Collectively,the cellular factor M2PK that is expressed in thymocytes could facilitate the transcription of HIV-1.