Pof8 is a La-related protein and a constitutive component of telomerase in fission yeast. Pof8 is a La-related protein and a constitutive component of telomerase in fission yeast

Telomerase reverse transcriptase (TERT) and the noncoding telomerase RNA (TR) subunit constitute the core of telomerase. We now report that the putative F-box protein Pof8 is also a constitutive component of active telomerase in fission yeast. Pof8 functions in a hierarchical assembly pathway by promoting the binding of the Lsm2-8 complex to telomerase RNA, which in turn promotes binding of the catalytic subunit. Loss of Pof8 reduces TER1 stability, causes a severe assembly defect and results in critically short telomeres. Structure profile searches identified similarities between Pof8 and telomerase subunits from ciliated protozoa, making Pof8 next to TERT the most widely conserved telomerase subunits identified to date. Overall design: Differential gene expression of pof8 deletion (strain PP1723) versus wildtype (strain PP138). There are 3 replicates for the pof8 deletion samples and 3 replicates for the isogenic control samples. RNA libraries from Lsm8 and control immunoprecipitations were prepared following instructions for Solexa mRNA sequencing and each sample was sequenced on a single lane of the Illumina GAIIx sequencer producing 40bp single-end unstranded reads.