CHARACTERIZATION OF HUMAN TELOMERASE COMPLEX

Telomerase, a ribonucleoprotein complex, adds hexameric repeats called ''telomeres'' to the growing ends of chromosomal DNA. Characterizatio n of mammalian telomerase has been elusive because of its low level of expression, We describe a bioinformatics approach to enrich and chara cterize the human telomerase complex. Using local sequence homology se arch methods, we detected similarity of the Tetrahymena p80 subunit of telomerase with the autoantigen Ro60, Antibodies to Ro60 immunoprecip itated the telomerase activity, Ro60 and p80 proteins were cross-recog nizable by antibodies to either protein, Telomerase activity and the R NA component of telomerase complex were localized to a doublet in a na tive gel from the Ro60 antibody-precipitated material, The enriched ma terial showed specific binding to a TTA GGG probe in vitro in an RNA t emplate-dependent manner, Polyclonal antibodies to the doublet also im munoprecipitated the telomerase activity. These results suggest an evo lutionary conservation of the telomerase proteins.