Molecular cloning and characterization of AtTERT, a telomerase reverse transcriptase homolog in Arabidopsis thaliana

On the basis of its predicted homology to human telomerase reverse transcriptase (hTERT), a cDNA for Arabidopsis thaliana TERT (AtTERT) has now been isolated from cultured cells. The cDNA contains an open reading frame of 3372 bp, encoding a protein with a predicted size of 131 kDa and isoelectric point of 9.9. The AtTERT protein contains the conserved reverse transcriptase motifs 1, 2 and A-E as well as the TERT-specific T motif. Reverse transcription-polymerase chain reaction analysis and an assay of telomerase activity revealed that both AtTERT mRNA and telomerase activity are abundant in shoot apical meristems but are not detectable in rosette leaves.