lecture 1 lo1

What is the one feature that all transcription factors always have?

DNA-binding domain.

What does the DNA-binding domain do?

directs transcription factors

to highly specific regions of the genome

by giving them a strong affinity for specific DNA sequences.

What other domains may transcription factors have besides a DNA-binding domain?

dimerisation domain,

a ligand binding domain,

an activation or repression domain,

a disordered region (unstructured flexible portion),

protein-protein interaction domains.

Approximately how many transcription factors are found in the human proteome?

Over 1,400

What is the consequence of having over 1,400 transcription factors in humans?

enormous potential for specific gene regulation control.

What are general transcription factors?

expressed in all cell types

form the pre-initiation complex

to initiate transcription.

What are lineage-specific (or master) transcription factors?

expressed in a highly cell-type-specific manner

bind to accessible regions of chromatin

regulate cell fate.

What is the unique ability of pioneer transcription factors?

They have the capacity to bind to inaccessible DNA regions that are occupied by nucleosomes.

What do pioneer transcription factors do after binding to inaccessible DNA?

They recruit remodelers to alter chromatin structure.

What are nuclear receptor transcription factors?

have induced DNA-binding activity after binding a ligand,

allowing rapid adaptation to signals like hormones