Component of the telomerase ribonucleoprotein complex that is essential for the replication of chromosome termini (PubMed:19179534). Component of the vault particle, which is a massive ribonucleoprotein complex that may play a role in cargo transport and signal transduction (By similarity). Responsible for the localizing and stabilizing vault RNA (vRNA) association in the vault ribonucleoprotein particle. Binds to TERC (By similarity). {ECO:0000250|UniProtKB:P97499, ECO:0000269|PubMed:19179534}. This is the function of TEP1 (telomerase associated protein 1, Ensembl gene identifier ENSG00000129566).