Conserved N-terminal motifs of telomerase reverse transcriptase required for ribonucleoprotein assembly in vivo.

摘要: Telomerase is a ribonucleoprotein (RNP) reverse transcriptase responsible for the maintenance of one strand telomere terminal repeats. The key protein subunit telomerase complex, known as TERT, possesses (RT)-like motifs that directly mediate nucleotide addition. RT are located in C-terminal region polypeptide. Sequence alignments also revealed existence four conserved (named GQ, CP, QFP, and T) N-terminal TERT. GQ motif yeast TERT has been demonstrated previously to be essential catalysis may participate RNP formation. In this report, we show substitution residues T impairs both activity, thus confirming validity sequence alignment. extent shortening correlates with reduction level protein, TERT-associated TLC1 RNA. Overexpression mutant proteins does not result shortening, implying assembly rather than catalytic function was affected. This notion further supported by comparing efficiency formation wild type overexpression strains. Taken together, our results three required efficient vivo but enzymatic telomerase. We majority telomerase-associated RNA more upstream 3' end reported, consistent additional processing events during maturation.