Studies on activity and interactions of human telomerase

It is reported that a single stranded region at 5'-terminus of human telomerase RNA (hTR) affects telomerase activity, though the sequences of the region are not conserved among vertebrate species. The mechanism of this phenomenon is not known. We examined binding affinity of an RNA oligomer (R17), which corresponds to the single stranded region (1-17) at 5'-terminus of hTR, to deletion variants of hTR. R17 showed higher affinity toward the 3'-half part of hTR than that for the 5'-half part. We chose two regions of the 3'-half part, where R17 is assumed to bind, and prepared variants of hTR in the single stranded region and the selected regions. The interactions and telomerase activities of these variants were examined. We also prepared an RNA interaction domain of the protein component (hTERT) of telomerase and its variants and tried to elucidate influence on interactions with hTR.