Reference - PMID:31131414 - Casein kinase 2 regulates telomere protein complex formation through Rap1 phosphorylation.

Reference summary

PubMed ID

PMID:31131414

Title

Casein kinase 2 regulates telomere protein complex formation through Rap1 phosphorylation.

Authors

Inoue H, Horiguchi M, Ono K, Kanoh J

Citation

Nucleic Acids Res 2019 Jul 26;47(13):6871-6884

Publication year

2019

Abstract

Telomeres located at the ends of linear chromosomes play important roles in the maintenance of life. Rap1, a component of the shelterin telomere protein complex, interacts with multiple proteins to perform various functions; further, formation of shelterin requires Rap1 binding to other components such as Taz1 and Poz1, and telomere tethering to the nuclear envelope (NE) involves interactions between Rap1 and Bqt4, a nuclear membrane protein. Although Rap1 is a hub for telomere protein complexes, the regulatory mechanisms of its interactions with partner proteins are not fully understood. Here, we show that Rap1 is phosphorylated by casein kinase 2 (CK2) at multiple sites, which promotes interactions with Bqt4 and Poz1. Among the multiple CK2-mediated phosphorylation sites of Rap1, phosphorylation at Ser496 was found to be crucial for both Rap1-Bqt4 and Rap1-Poz1 interactions. These mechanisms mediate proper telomere tethering to the NE and the formation of the silenced chromatin structure at chromosome ends.

Annotation