Genetik 2_Regulation of Gene Expression in Eukaryotes

A DNA element that prevents the spread of heterochromatin by serving as a binding site for proteins that maintain euchromatic modifications such as histone acetylation

changes in nucleosome position along DNA.

A special class of eukaryotic regulatory complex that serves as a bridge along together regulatory proteins and RNA polymerase.

A repressor that facilitates gene repression but is not itself a DNA-binding repressor.

Unmethylated CG dinucleotides found in clusters near gene promoters.

The process in organisms using a chromosomal sex-determination mechanism that allows standard structural genes on the sex chromosome to be expressed at the same levels in females and males, regardless of the number of sex chromosomes. In mammals, dosage compensation operates by maintaining only a single active X chromosome in each cell. In Drosophila, it operates by hyperactivating the male X chromosome.

The macromolecular assembly responsible for interaction between elements and the promoter regions of genes.

A set of regulatory proteins consisting of transcription factors that bind to cis-acting regulatory sequences in the DNA.

Regulatory elements positioned between a promoter and an enhancer. Their presence prevents the promoter from being activated by the enhancer.

Heritable modifications in gene function not due to changes in the base sequence of the DNA of the organism. Examples of epigenetic inheritance are paramutation, X chromosome inactivation, and parental imprinting.

A heritable alteration, such as DNA methylation or a histone modification, that leaves the DNA sequence unchanged.

A less-condensed chromosomal region, thought to contain most of the normally functioning genes.

A phenomenon in which a gene inherited from one of the parents is not expressed, even though both gene copies are functional. Imprinted genes are methylated and inactivated in the formation of male or female gametes.

DNA sequence with one methylated and one unmethylated strand.

Densely staining condensed chromosomal regions, believed to be for the most part genetically inert.

Refers to the pattern of modification (acetylation, modification, phosphorylation) of the histone tails that may carry information required for correct chromatin assembly.

This enzymatic activity that removes an acetyl group from a histone tail, which promotes the repression of a gene transcription.

covalent alteration of one or more AS residues of the histone protein. Modifications include acetylation, phosphorylation and methylation.

A type of basic protein that forms the unit around which DNA is coiled in the nucleosomes of eukaryotic chromosomes.

The end of a histone protein protruding from the core nucleosome and subjected to post-translational modification. Also histone code.

An overabundance of acetyl groups attached to certain AS of the histone tails. Transcriptionally active chromatin is usually hyperacetylated.

An underabundance of acetyl groups on certain AS of the histone tails. Transcriptionally inactive chromatin.

The expression of a gene only when inherited from the father, because the copy of the gene form the mother is inactive due to methylation in the course of gamete formation.

A protein complex that acts as an adaptor that interacts with transcription factors bound to regulatory sites and with general initiation factors for RNA polymerase II-mediated transcription.

The expression of a gene only when inherited from the mother, because the copy of the gene form the father is inactive due to methylation in the course of gamete formation.

Variegation caused by the inactivation of a gene in some cells through its abnormal juxtaposition with heterochromatin.

Occurs when the mRNA of a particular gene is destroyed or its translation blocked. The mechanism of gene silencing usually involves RNAi or miRNA.

The series of transcription-factor binding sites located near the core promoter.

A gene whose phenotypic expression is easy to monitor, used to study tissue-specific promoter and enhancer activites in transgenes.

A feature of eukaryotic regulatory proteins for which the transcriptional activation mediated by the interaction of several proteins is greater than the sum of the effects of the proteins taken individually.

Occurs when a gene cannot be translated because it is located in heterochromatin.

A DNA sequence of yeast located 5' of the gene promoter, a transcription factor binds to the UAS to psitively regulate gene expression.