Centromere RNA Is Negatively Regulated by Cbf1 and Its Unscheduled Synthesis Impacts CenH3 Binding.

Title Centromere RNA Is Negatively Regulated by Cbf1 and Its Unscheduled Synthesis Impacts CenH3 Binding.
Publication TypeJournal Article
Year of Publication2019
AuthorsChen, C-F, Pohl, TJ, Chan, A, Slocum, JS, Zakian, VA
Date Published2019 Oct
KeywordsBasic Helix-Loop-Helix Leucine Zipper Transcription Factors, Centromere, Chromatin, Chromosomal Proteins, Non-Histone, Chromosome Segregation, DNA Helicases, Histones, Kinetochores, Nucleosomes, RNA, Fungal, RNA, Untranslated, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins

<p>Two common features of centromeres are their transcription into noncoding centromere RNAs (cen-RNAs) and their assembly into nucleosomes that contain a centromere-specific histone H3 (cenH3). Here, we show that cen-RNA was present in low amounts in wild-type (WT) cells, and that its appearance was tightly cell cycle-regulated, appearing and disappearing in a narrow window in S phase after centromere replication. In cells lacking Cbf1, a centromere-binding protein, cen-RNA was 5-12 times more abundant throughout the cell cycle. In WT cells, cen-RNA appearance occurred at the same time as loss of Cbf1's centromere binding, arguing that the physical presence of Cbf1 inhibits cen-RNA production. Binding of the Pif1 DNA helicase, which happens in mid-late S phase, occurred at about the same time as Cbf1 loss from the centromere, suggesting that Pif1 may facilitate this loss by its known ability to displace proteins from DNA. Cen-RNAs were more abundant in Δ cells but only in mid-late S phase. However, fork pausing at centromeres was not elevated in Δ cells but rather was due to centromere-binding proteins, including Cbf1 Strains with increased cen-RNA lost centromere plasmids at elevated rates. In Δ cells, where both the levels and the cell cycle-regulated appearance of cen-RNA were disrupted, the timing and levels of cenH3 centromere binding were perturbed. Thus, cen-RNAs are highly regulated, and disruption of this regulation correlates with changes in centromere structure and function.</p>

Alternate JournalGenetics
PubMed ID31391265
PubMed Central IDPMC6781895
Grant ListR35 GM118279 / GM / NIGMS NIH HHS / United States