RT Journal Article
SR Electronic
T1 Evaluations of short telomere risk-associated single nucleotide polymorphisms in telomerase reverse transcriptase gene on telomere length maintenance
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 552133
DO 10.1101/552133
A1 Jialin Xu
A1 Matthew A. Trudeau
A1 Andrew J. Sandford
A1 Judy M.Y. Wong
YR 2019
UL http://biorxiv.org/content/early/2019/02/15/552133.abstract
AB Telomere biology disorders (TBDs) refer to a spectrum of tissue degenerative disorders caused by genetic mutations in telomere biology genes. Most patients with TBDs suffer from telomere maintenance defects secondary to telomerase deficiency. While the highly penetrant mutations in the telomerase reverse transcriptase (TERT) gene that drive disease onset and progression of TBDs are relatively rare, there exist several single nucleotide polymorphisms (SNPs) in TERT that have been linked to various diseases in the TBD spectrum. In this study, we investigated the biochemical properties of five TERT variants. In an ex vivo cell model, we found that primary human fibroblasts expressing nonsynonymous TERT SNPs had comparable cell growth kinetics to primary cells expressing WT-TERT, while a parallel vector control expressing-cell line entered replicative senescence. At the molecular level, primary cells expressing the minor alleles of two of the five TERT variants (A279T, ΔE441) had replication-dependent loss of telomere length. In an in vitro primer extension assay, these two variants showed reduced telomerase nucleotide addition processivity. Together, our data suggested that selective, common TERT variants could be revealed to harbour telomere maintenance defects, leading to a plausible explanation for their observed associations to telomere biology disorders.