Paramecium tetraurelia chromatin assembly factor-1-like protein PtCAF-1 is involved in RNA-mediated control of DNA elimination. Issue 19 (30th September 2014)

• Record Type: Journal Article
• Authors: Ignarski, Michael; Singh, Aditi; Swart, Estienne C.; Arambasic, Miroslav; Sandoval, Pamela Y.; Nowacki, Mariusz
• Is Part Of: Nucleic acids research. Volume 42:Issue 19(2014)
• Page Start: 11952
• Page End: 11964
• Publication Date: 2014-09-30
• Subjects: Nucleic acids -- Periodicals; Molecular biology -- Periodicals; 572.805
• DOI: 10.1093/nar/gku874
• Languages: English
• ISSNs: 0305-1048

Abstract

Abstract: Genome-wide DNA remodelling in the ciliate Paramecium is ensured by RNA-mediated trans-nuclear crosstalk between the germline and the somatic genomes during sexual development. The rearrangements include elimination of transposable elements, minisatellites and tens of thousands non-coding elements called internally eliminated sequences (IESs). The trans-nuclear genome comparison process employs a distinct class of germline small RNAs (scnRNAs) that are compared against the parental somatic genome to select the germline-specific subset of scnRNAs that subsequently target DNA elimination in the progeny genome. Only a handful of proteins involved in this process have been identified so far and the mechanism of DNA targeting is unknown. Here we describe chromatin assembly factor-1-like protein (PtCAF-1), which we show is required for the survival of sexual progeny and localizes first in the parental and later in the newly developing macronucleus. Gene silencing shows that PtCAF-1 is required for the elimination of transposable elements and a subset of IESs. PTCAF-1 depletion also impairs the selection of germline-specific scnRNAs during development. We identify specific histone modifications appearing during Paramecium development which are strongly reduced in PTCAF-1 depleted cells. Our results demonstrate the importance of PtCAF-1 for the epigenetic trans-nuclear cross-talk mechanism.