Gene Expression Flashcards
What is differential gene expression?
Multicellular organisms have the same genes in all cells, but cells at different areas of the body express genes differently (specialised genes are expressed at their specific tissues). This happens due to a series of signalling events and regulation of gene regulatory proteins (transcriptional control).
Sites on DNA for protein binding:
- enhancer seq
- silencer seq
- promoter seq
Promoter seq on DNA includes binding sites such as:
- regulatory protein binding site
- transcriptional factor binding site
- RNA polymerase II binding site
How do transcriptional factors interact with DNA?
Transcriptional factors bind to TATA-binding protein that in turns bind to TATA box on DNA.
Examples of DNA-binding proteins and site of binding:
- activator (binds to enhancer seq)
- repressor (binds to silencer seq)
- TATA-binding protein (binds to TATA box)
- RNA polymerase II (binds to rna poly binding site)
What is modular domain?
Modular domain is the subunit on the transcriptional protein that regulates the interaction of that protein with other proteins (determines the binding partner for that protein)
What are motifs?
Motifs are the structure of the DNA-binding domain within a DNA-binding protein
Which are the 4 of the motifs?
- Leucine zipper (common)
- Helix-turn-helix (embryonic development)
- Helix-loop-helix (on activators, for binding to enhancer seq)
- Zinc finger
Function of non-DNA binding proteins:
They recognise the distinct surface created by DNA-binding protein and recruit other gene expression regulatory proteins such as activators/repressors.
7 types of gene regulatory protein regulation:
- Protein syn.
- Ligand binding
- Protein phosphorylation
- Addition of 2nd subunit
- Unmasking
- Stimulation of nuclear entry
- Release from membrane
RNAs involved in gene expression regulation:
- miRNA
- siRNA
- piRNA
How do the regulatory proteins gain access to the tightly coiled DNA?
There are mechanisms that alter the structure of the chromatin.
