Repeat Protein Products Production Possible From Telomeric RNA, Study Suggests

A pair of University of North Carolina-Chapel Hill researchers reporting in the Proceedings of the National Academy of Sciences consider the proteins produced through the translation of a guanine-rich RNA sequence called TERRA — an RNA produced by transcribing the repeat sequences found in telomeres. Based on predictions suggesting TERRA translation would lead to the production of a charged repeating valine-arginine (VR) protein and a hydrophobic repeating glycine-leucine (GL) protein, the team synthesized each of the dipeptides and used an anti-VR antibody to track the protein's interactions and location within the cell, using gene knockdown experiments to uncover a boost in VR levels in cells with altered telomere function. "These observations suggest that telomeres, in particular in cells undergoing telomere dysfunction, may express two dipeptide repeat proteins with potentially strong biological properties," they write, noting that the abundance of the repeating dipeptide proteins in question "could alter nucleic acid metabolism and general protein synthesis and trigger cellular inflammation responses." Given these and results, UNC researcher and senior author Jack Griffith speculates in a statement that blood-based tests for the proteins may one day be used to screen for some human diseases or telomere features relevant to aging.