Nucleic acid compositions comprising a region and a TERT minimal promoter activator binding site that acts to activate transcription of the telomerase reverse transcriptase (TERT) coding sequence, as well as vectors and constructs including the same, are provided. Also provided are methods of modulating, e.g., inhibiting, the TERT transcription activation activity of the subject TERT activator binding site regions in order to regulate, e.g., repress, telomerase expression, which methods find use in a variety of different applications, including the therapeutic applications and the like. In addition, methods of screening for agents that modulate the TERT transcription activating activity of the subject TERT activator sites are provided. The subject invention finds use in, among other applications, the regulation of TERT expression.