How do transcription factors regulate gene expression in eukaryotes?

How do transcription factors regulate gene expression in eukaryotes?

Gene expression in eukaryotic cells is regulated by repressors as well as by transcriptional activators. Like their prokaryotic counterparts, eukaryotic repressors bind to specific DNA sequences and inhibit transcription. Other repressors compete with activators for binding to specific regulatory sequences.

How do chromatin modifications regulate transcription?

Functional Consequences of Histone Modifications To establish a global chromatin environment, modifications help partition the genome into distinct domains such as euchromatin, where DNA is kept “accessible” for transcription, and heterochromatin, where chromatin is “inaccessible” for transcription.

How do transcription factors regulate gene expression?

Transcription factors are vital molecules in the control of gene expression, directly controling when, where and the degree to which genes are expressed. They bind to specific sequences of DNA and control the transcription of DNA into mRNA.

What is a transcription factor and how can it regulate gene expression do transcription factors always activate gene expression?

Transcription factor, molecule that controls the activity of a gene by determining whether the gene’s DNA (deoxyribonucleic acid) is transcribed into RNA (ribonucleic acid). The enzyme RNA polymerase catalyzes the chemical reactions that synthesize RNA, using the gene’s DNA as a template.

How does transcription work in eukaryotes?

Eukaryotic transcription occurs within the nucleus where DNA is packaged into nucleosomes and higher order chromatin structures. Protein coding genes are transcribed by RNA polymerase II into messenger RNAs (mRNAs) that carry the information from DNA to the site of protein synthesis.

What are the transcription factors in eukaryotes?

Eukaryotic transcription factors are modular proteins that utilize distinct domains for transcriptional activation (or repression) and DNA binding.

How does chromatin regulate gene expression?

In eukaryotes, the tight or loose packaging of the genes in chromatin (DNA plus specific proteins) can control whether the genes can be expressed to form their encoded product. DNA itself can be methylation and that also regulates gene expression, generally to turn off the gene. …

What role do chromatin remodelers play in eukaryotic gene expression?

What role do chromatin remodelers play in eukaryotic gene expression? Chromatin remodeler enzymes can enzymatically change the distribution or composition of nucleosomes (histone octamers). a eukaryotic cis-acting DNA regulatory sequence to which transacting factors bind and stimulate transcription.

How does chromatin structure affect gene expression?

Chromatin structure plays a key role in regulating gene expression by allowing DNA accessibility to transcriptional machinery and transcription factors [12].

How can chromatin be modified?

To form chromatin, DNA is tightly condensed by being wrapped around nuclear proteins called histones. Epigenetic modifications to histone proteins such as methylation/demethylation and acetylation/deacetylation can alter the structure of chromatin resulting in transcriptional activation or repression.

What does transcription in eukaryotes require?

Eukaryotic transcription is carried out in the nucleus of the cell and proceeds in three sequential stages: initiation, elongation, and termination. Eukaryotes require transcription factors to first bind to the promoter region and then help recruit the appropriate polymerase.

What happens during transcription in eukaryotes quizlet?

During transcription, RNA polymerase seperates DNA strands and uses one of the strands as a template to assemble nucleotides into a complementary strand of RNA. DNA sequences bind in the regulatory regions of eukaryotic genes and transcription factor ps control the expression of those genes.

How is chromatin used to regulate gene expression?

The word chromatinrefers to DNA in complex with proteins, as it naturally exists in the nucleus of eukaryotic cells. Tightly packaged DNA in the nucleus is wound around specific proteins called histones. Both DNA and histones can be chemically modified to regulate gene expression.

How is transcription of genes regulated in eukaryotes?

Eukaryotic Transcription Gene Regulation. Like prokaryotic cells, the transcription of genes in eukaryotes requires the actions of an RNA polymerase to bind to a sequence upstream of a gene to initiate transcription.

How does histone modification affect gene expression in eukaryotes?

Histone modification ( acetyl, methyl) –> DNA methylation decrease gene expression. DNA acetylation increase gene expression Chromatin remodeling chromatin remodeling A mechanism for epigenetic gene regulation by the alteration of chromatin structure. the way the chromatin is wrapped (wrapping variations) core can be remodeled

Where does a transcription factor bind to the promoter?

When transcription factors bind to the promoter just upstream of the encoded gene, it is referred to as a cis-acting element, because it is on the same chromosome just next to the gene. The region that a particular transcription factor binds to is called the transcription factor binding site.