What is the role of a transcription factor?

In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence.

Thereof, what is an enhancer in eukaryotic cells?

In some eukaryotic genes, there are regions that help increase or enhance transcription. These regions, called enhancers, are not necessarily close to the genes they enhance. They can be located upstream of a gene, within the coding region of the gene, downstream of a gene, or may be thousands of nucleotides away.

What is an enhancer in transcription?

In genetics, an enhancer is a short (50–1500 bp) region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur. These proteins are usually referred to as transcription factors.

What are the transcription factors and what do they do?

Transcription factors are proteins involved in the process of converting, or transcribing, DNA into RNA. Transcription factors include a wide number of proteins, excluding RNA polymerase, that initiate and regulate the transcription of genes.

What are positive and negative transcription factors?

In negative regulation a repressor protein binds to an operator to prevent a gene from being expressed. In positive regulation a transcription factor is required to bind at the promoter in order to enable RNA polymerase to initiate transcription.

Is p53 is a transcription factor?

The p53 tumor suppressor protein is widely known for its role as a transcription factor that regulates the expression of stress response genes and mediates a variety of anti-proliferative processes.

How are transcription factors made?

The DNA loops like cooked spaghetti to bring far-off binding sites and transcription factors close to general transcription factors or “mediator” proteins. Transcription factors are proteins, so they are encoded by genes and made via gene expression (transcription and translation).

How do enhancers differ from promoters as cis acting regulatory sequences in eukaryotes?

Enhancers are cis-acting sequences that can greatly increase transcription rates from promoters on the same DNA molecule; thus, they act to activate, or positively regulate, transcription. Different DNA sequences serve as target-recognition sites for specific trans-acting regulatory proteins.

What is an enhancer in transcription?

In genetics, an enhancer is a short (50–1500 bp) region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur. These proteins are usually referred to as transcription factors.

What controls the genes?

Each eukaryote gene is transcribed separately, with separate transcriptional controls on each gene. Whereas prokaryotes have one type of RNA polymerase for all types of RNA, eukaryotes have a separate RNA polymerase for each type of RNA. One enzyme for mRNA-coding genes such as structural proteins.

How do transcription factors regulate gene expression?

Transcription factors are proteins involved in the process of converting, or transcribing, DNA into RNA. Transcription factors include a wide number of proteins, excluding RNA polymerase, that initiate and regulate the transcription of genes. Regulation of transcription is the most common form of gene control.

What does it mean to say that genes are regulated?

Gene regulation is the informal term used to describe any mechanism used by a cell to increase or decrease the production of specific gene products (protein or RNA). Cells can modify their gene expression patterns to trigger developmental pathways, respond to environmental stimuli, or adapt to new food sources.

What is the function of the basal transcription factors?

General transcription factors (GTFs), also known as basal transcriptional factors, are a class of protein transcription factors that bind to specific sites (promoter) on DNA to activate transcription of genetic information from DNA to messenger RNA.

What is the sigma factor?

A sigma factor (σ factor) is a protein needed only for initiation of transcription. It is a bacterial transcription initiation factor that enables specific binding of RNA polymerase to gene promoters.

How do transcription factors work?

Transcription factors are a very diverse family of proteins and generally function in multi-subunit protein complexes. They may bind directly to special “promoter” regions of DNA, which lie upstream of the coding region in a gene, or directly to the RNA polymerase molecule.

Where does synthesis of transcription factor proteins occur?

Nuclear localization. In eukaryotes, transcription factors (like most proteins) are transcribed in the nucleus but are then translated in the cell’s cytoplasm. Many proteins that are active in the nucleus contain nuclear localization signals that direct them to the nucleus.

Do prokaryotes have transcription factors?

Eukaryotes have three types of RNA polymerases, I, II, and III, and prokaryotes only have one type. Eukaryotes form and initiation complex with the various transcription factors that dissociate after initiation is completed. There is no such structure seen in prokaryotes. These events do not occur in prokaryotes.

How does alternative splicing function as a control of gene expression?

Splicing can be regulated so that different mRNAs can contain or lack exons, in a process called alternative splicing. Alternative splicing allows more than one protein to be produced from a gene and is an important regulatory step in determining which functional proteins are produced from gene expression.

What is the process of transcription?

Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). DNA safely and stably stores genetic material in the nuclei of cells as a reference, or template.

What is alternative splicing?

Alternative splicing, or differential splicing, is a regulated process during gene expression that results in a single gene coding for multiple proteins. In this process, particular exons of a gene may be included within or excluded from the final, processed messenger RNA (mRNA) produced from that gene.

Where does RNA polymerase bind and why?

In order to start a new round of transcription, the core RNA polymerase has to be directed to bind at a promoter, defined as the specific DNA sequence where transcription is initiated. There are specific DNA binding factors that bind to promoters and to RNA polymerase.

How does gene regulation makes cell specialization possible?

at the same time. They can conserve energy and resources by regulating their activities, producing only those genes necessary for the cell to function. In prokaryotes, DNA-binding proteins regulate genes by controlling transcription. Complex gene regulation in eukaryotes makes cell specialization possible.

Are transcription factors enzymes?

Transcription factors perform this function alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) the recruitment of RNA polymerase (the enzyme that performs the transcription of genetic information from DNA to RNA) to specific genes.

What is translational control?

Translational control is widely used to regulate gene expression. This mode of regulation is especially relevant in situations where transcription is silent or when local control over protein accumulation is required.

Leave a Comment