Document Actions
Three Ever Shorter Telomere EST genes ar ... vitro yeast telomerase activity
Three Ever Shorter Telomere (EST) genes are dispensable for in vitro yeast telomerase activity.
68
Telomerase is a specialized reverse transcriptase consisting of both RNA and protein components. Previous characterization of yeast telomerase function in vivo identified four EST (for ever shorter telomeres) genes that, when mutated, result in the phenotypes expected for a defect in telomerase. Consistent with this genetic prediction, the EST2 gene has recently been shown to encode the catalytic component of telomerase. Using an in vitro assay, we show here that telomerase activity is present in extracts prepared from yeast strains carrying est1-Delta, est3-Delta, and cdc13-2(est) mutations. Therefore, while these three genes are necessary for telomerase function in vivo, they do not encode components essential for core catalytic activity. When Est2p, the one EST gene product found to be essential for catalytic activity, was immunoprecipitated from extracts, the telomerase RNA subunit was also specifically precipitated, supporting the conclusion that these two components are in a stable complex.
Lingner J, Cech TR, Hughes TR, Lundblad V
Proceedings of the National Academy of Sciences of the United States of America
1997-10-14 00:00
94
21
11190-5
Centrifugation, Density Gradient,Cyclin B,Fungal Proteins,Genes, Fungal,Mutagenesis,Polymerase Chain Reaction,Proteins,Saccharomyces cerevisiae,Saccharomyces cerevisiae Proteins,Telomerase,Telomere,Telomere-Binding Proteins,Cdc13 protein, S cerevisiae,Cyclin B,EST1 protein, S cerevisiae,EST3 protein, S cerevisiae,EST3 protein, fungus,Fungal Proteins,Proteins,Saccharomyces cerevisiae Proteins,Telomere-Binding Proteins,Telomerase
Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215, USA
Proc. Natl. Acad. Sci. U.S.A.
0027-8424
308
True
9326584
