. . . . . . "Cyclin T2 competes with cyclin T1 for binding to CDK9 and can thereby inhibit HIV-1 Tat activity" . "Amino acids 260-263 of cyclin T1 are critical for HIV-1 Tat-mediated transcriptional activation, and site-directed mutations in this region of cyclin T2 (asparagine to cysteine at residue 260) allow it to bind Tat and stimulate transcription" . "inhibited by" . "binds" .