Project description:FA-SAT is a satellite DNA sequence present and transcribed in many Bilateria species, what may anticipate a conserved and significant function in these genomes. Here we prove that in cat and human cells, FA-SAT satellite transcripts play a nuclear function at the G1 phase of the cell cycle. We identified and demonstrated that the main FA-SAT non-coding RNA interactor is the PKM2 protein. Our work shows that the disruption of the FA-SAT ncRNA/PKM2 protein complex, by the depletion of either FA-SAT or PKM2, results in the same phenotype—apoptosis. Moreover, the ectopic overexpression of FA-SAT in tumour human cells did not affect the cell cycle progression. In sum, our data reveal a new player, FA-SAT RNA, a non-coding satellite RNA, which interacts with the PKM2 nuclear protein. This ribonucleoprotein is involved in apoptosis and cell cycle progression, what foresees a promising new target for studies in cancer processes that rely on these pathways.
Project description:We report the sequences bound to CENP-A in the dog genome (Canis familiaris) for high-throughput characterization of centromeric sequences. We compare these ChIPSeq reads (72 bp, single read) against a reference centromeric satellite DNA domain database for the dog genome, resulting in the annotation of sequence variation and estimated abundance of seven satellite families together with adjacent, non-satellite sequences. To study global patterns of sequence diversity and characterizing the subset of sequences correlated with centromere function, these sequences were evaluated relative to a comprehensive centromere sequence domain k-mer library. From this analysis, we identify functional sequence features from two satellite families (CarSat1 and CarSat2) that are defined by distinct arrays subtypes. Sequences bound to CENP-A in MDCK (dog) cell line
Project description:We used native ChIP-seq of CENP-A-containing particles from normal centromeres on alpha-satellite DNA and three naturally-occurring neocentromeres to test the proposed models for the major form of the fundamental repeating unit of centromeric chromatin. We found that the predominant form of the CENP-A particle at the centromere is an octameric nucleosome with loose terminal DNA. Additionally, we found CENP-A nucleosomes are strongly phased on the 171 bp alpha-satellite monomers of normal centromeres, and also display strong positioning and neocentromeres. Comparison of CENP-A and bulk nucleosome DNA lengths and positions in three different human neocentromere-containing cell lines
Project description:Centromeres, the sites of spindle attachment during mitosis and meiosis, are located in specific positions in the human genome, normally coincident with diverse subsets of alpha satellite DNA. While there is strong evidence supporting the association of some subfamilies of alpha satellite with centromere function, the basis for establishing whether a given alpha satellite sequence is or is not designated a functional centromere is unknown, and attempts to understand the role of particular sequence features in establishing centromere identity have been limited by the near identity and repetitive nature of satellite sequences. Utilizing a broadly applicable experimental approach to test sequence competency for centromere specification, we have carried out a genomic and epigenetic functional analysis of endogenous human centromere sequences available in the current human genome assembly. The data support a model in which functionally competent sequences confer an opportunity for centromere specification, integrating genomic and epigenetic signals and promoting the concept of context-dependent centromere inheritance. Sequences bound to CENP-A in HuRef cell line