BIOL 483 Lecture Notes - Lecture 51: Lamin B2, X-Inactivation, Gene Silencing
Document Summary
Epigenetic modification of gene expression where previously active genes are inactivated. Can happen to individual genes or larger chromosome regions. Involves changes in chromatin structure, levels of dna methylation, affect mrna stability. Once you collect methylated histones and further compact genes in heterochromatin, you get silencing. Have methylated cpg sites - if occur at promoter regions -> block tf binding. Cpg binding proteins with methyl binding proteins recruit chromatin silencers (eg. hdacs) Major player in eukaryotic system in gene silencing in heterochromatin. Non histone chromosomal protein that interacts with genes. Binds to centromeres, telomeres, silenced regions (eg inactive x) Can localise at nuclear periphery through interactions with lamin b (envelope protein) -> sequester heterochromatin and decreases likelihood that dna elements will be integrated elsewhere in genome. We have tight nucleosomal arrays - short linkers that are easy to interdigitate and compact. Can characterize regions by boundary elements that border them.
