Proteomics of yeast telomerase identified Cdc48-Npl4-Ufd1 and Ufd4 as regulators of Est1 and telomere length.

TitleProteomics of yeast telomerase identified Cdc48-Npl4-Ufd1 and Ufd4 as regulators of Est1 and telomere length.
Publication TypeJournal Article
Year of Publication2015
AuthorsLin, K-W, McDonald, KR, Guise, AJ, Chan, A, Cristea, IM, Zakian, VA
JournalNat Commun
Date Published2015 Sep 14
KeywordsAdenosine Triphosphatases, Blotting, Southern, Blotting, Western, Cell Cycle Proteins, Mass Spectrometry, Nucleocytoplasmic Transport Proteins, Proteomics, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Tandem Mass Spectrometry, Telomerase, Telomere Homeostasis, Ubiquitin-Protein Ligases, Vesicular Transport Proteins

<p>Almost 400 genes affect yeast telomere length, including Est1, which is critical for recruitment and activation of telomerase. Here we use mass spectrometry to identify novel telomerase regulators by their co-purification with the telomerase holoenzyme. In addition to all known subunits, over 100 proteins are telomerase associated, including all three subunits of the essential Cdc48-Npl4-Ufd1 complex as well as three E3 ubiquitin ligases. The Cdc48 complex is evolutionarily conserved and targets ubiquitinated proteins for degradation. Est1 levels are ∼40-fold higher in cells with reduced Cdc48, yet, paradoxically, telomeres are shorter. Furthermore, Est1 is ubiquitinated and its cell cycle-regulated abundance is lost in Cdc48-deficient cells. Deletion of the telomerase-associated E3 ligase, Ufd4, in cdc48-3 cells further increases Est1 abundance but suppresses the telomere length phenotype of the single mutant. These data argue that, in concert with Ufd4, the Cdc48 complex regulates telomerase by controlling the level and activity of Est1.</p>

Alternate JournalNat Commun
PubMed ID26365526
PubMed Central IDPMC4579843
Grant ListDA026192 / DA / NIDA NIH HHS / United States
GM43265 / GM / NIGMS NIH HHS / United States
HD073044 / HD / NICHD NIH HHS / United States
R01 GM114141 / GM / NIGMS NIH HHS / United States