Cell Nucleus

Components of the Promoter
C) Distal promoter. Contains response elements. -500 to -1000
bases.
Response elements. Special DNA sequence which bind to
proteins called specific transcription factors
Transcription factor
GR
Response element
GRE
500 to 1000 bases
TATA
RNA polymerase
Specific proteins called transcription factors may activate or
repress transcription activity. Specific to one gene (or a few genes)
The cell controls gene activity by regulating the presence or
absence of the specific transcription factor.
Eg. Cyclic AMP activates CREB, which binds to its own response
element and then turns on a gene
Transcription factors are often activated by dimerization
Every gene has its own set of response elements. – an integrating
function.
8
Thursday, January 21, 2010