Identification and characterization of the Schizosaccharomyces pombe TER1 telomerase RNA.

Although the catalytic subunit of the Schizosaccharomyces pombe telomerase holoenzyme was identified over ten years ago, the unusual heterogeneity of its telomeric DNA made it difficult to identify its RNA component. We used a new two-step immunoprecipitation and reverse transcription-PCR technique to identify the S. pombe telomerase RNA, which we call TER1. TER1 RNA was 1,213 nucleotides long, similar in size to the Saccharomyces cerevisiae telomerase RNA, TLC1. TER1 RNA associated in vivo with the two known subunits of the S. pombe telomerase holoenzyme, Est1p and Trt1p, and neither association was dependent on the other holoenzyme component. We present a model to explain how telomerase introduces heterogeneity into S. pombe telomeres. The technique used here to identify TER1 should be generally applicable to other model organisms.