The Polycomb Repressive Complex 2 (PRC2) catalyzes genome transcription repression through the methylation of lysine residue 27 in the amino terminal region of histone 3 (H3K27me1/2/3) [2], [7]. PRC2 is made up of three highly conserved core subunits: Kmt6, Eed, and Suz12. Accurate distribution of PRC2 is essential for proper...
The process of expressing a gene involves not just binding of proteins and enzymes to DNA to produce first RNA and eventually proteins, but rather association of these transcription factors with chromatin and structural proteins called histones. When histone H3 is trimethylated at lysine 27 to produce H3K27me3, gene silencing...
Histones, as part of nucleosomes, are responsible for DNA packaging in chromosomes. They also affect DNA expression by a multitude of post-translational modifications, especially prevalent on the amino terminus of histones. Co-activator protein complexes “write”, “read”, or “erase” histone modifications, and in balance determine which sections of DNA are free...
PRC2 (Polycomb Repressive Complex 2) mediated gene silencing plays an important role in cell differentiation, stem cell plasticity, and tumor suppression. In fungi, it is also involved in pathogenicity. The catalytic subunit, KMT6, trimethylates lysine 27 on histone h3 (H3K27me3) at loci targeted for silencing. In animals, PRC1 and PRC2...
Polycomb Repressive Complex 2 (PRC2) is a histone methyltransferase that initiates facultative heterochromatin formation by trimethylating histone H3 on lysine 27 (H3K27me3). Mutations within its three primary subunits, KMT6, EED, and SUZ12, result in inherited diseases and sporadic cancers. In the fungus Fusarium graminearum, deletion of the gene encoding the...
Modifications of histone tail amino acid residues are necessary for many reactions involving chromatin. These processes can produce transcriptionally active, euchromatic, or inactive, heterochromatic, segments of DNA. The formation and maintenance of facultative heterochromatin is critical for the proper growth and development of many eukaryotes. Euchromatin can be changed into...
Mutation of repetitive DNA by repeat-induced point mutation (RIP) is a process that occurs in many filamentous fungi of the Ascomycota during the sexual cycle. Concurrently, direct DNA repeats are often deleted by homologous recombination at high frequency during the sexual cycle. Thus, the processes of RIP and deletion compete...
DNA is often described as the “blueprint for life”. In eukaryotes this information is contained within linear chromosomes of varying size and number. During cell division, the chromosomes must be faithfully segregated into each daughter cell to avoid disease and sustain life. This process is carried out by the kinetochore...
In eukaryotes, the defined loci on each chromosome, the centromeres, accomplish
the critical task of correct cell division. In some organisms, centromeres are
composed of a euchromatic central core region embedded in a stretch of
heterochromatin and the inheritance and maintenance of centromeres are controlled
by dynamic epigenetic phenomena. Although...