Transcription factor: Difference between revisions
mNo edit summary |
No edit summary |
||
| (3 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
In [[Gene expression|gene expression]], the transcription of DNA to RNA is controlled by proteins called transcription factors. In [[Eukaryote|eukaryotes]] there are 6 general transcription factors (GTFs): TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH, each of which | In [[Gene expression|gene expression]], the transcription of [[DNA|DNA]] to [[RNA polymerase II|RNA]] is controlled by [[Protein|proteins]] called transcription factors. In [[Eukaryote|eukaryotes]] there are 6 general transcription factors (GTFs): [[TFIIA|TFIIA]], [[TFIIB|TFIIB]], [[TFIID|TFIID]], [[TFIIE|TFIIE]], [[TFIIF|TFIIF]] and [[TFIIH|TFIIH]], each of which has a different role in regulating [[Gene transcription|gene transcription]]. All GTFs are multi-subunit, except for TFIIB. | ||
The GTFs are involved in the [[Preinitiation complex|preinitiation complex]] (PIC) assembly which positions [[RNA polymerase II|RNA polymerase II]] and separates the template strand at the transcription start site through a number of steps as outlined: | |||
#TFIIA facilitates and stabilises TFIID binding to the [[TATA box|TATA box]]. | |||
#TFIID recruits the single subunit factor TFIIB. | |||
#With this interaction, TFIIB recruits RNA polymerase II-TFIIF complex (TFIIF is joined to[[RNA polymerase II|RNA polymerase II]] before this recruitment.) | |||
#The recruitment of the RNA polymerase II-TFIIF allows TFIIE and then finally TFIIH to bind, completing the PIC assembly. | |||
This is known as the classical pathway; not all promoters are turned on in this way. | |||
=== Function of GTFs === | |||
'''TFIID''': Binds to the [[TATA box|TATA box]], recruits TFIIB | |||
'''TFIIA''': Stabilizes TFIID binding, anti repression function | |||
'''TFIIB''': Recruits RNA pol II-TFIIF, important for start site selection | |||
'''TFIIF''': Stimulates [[Elongation|elongation]], destabilizes non specific RNA pol II-DNA interactions | |||
'''TFIIE''': Recruits TFIIH and modulates TFIIH activity | |||
'''TFIIH''': [[Promoter|Promoter]] melting and [[Clearance|clearance]], CTD [[Kinase|kinase]] activity, DNA repair coupling<ref>Harvey L, Arnold B, Chris A, Monty K, Anthony B, Hidde P, Angelika A, Kelsey C, 2016, Molecular Cell Biology, 8th edition, New York: W. H. Freeman</ref> | |||
=== Reference === | |||
<references /> | |||
Latest revision as of 19:16, 23 October 2017
In gene expression, the transcription of DNA to RNA is controlled by proteins called transcription factors. In eukaryotes there are 6 general transcription factors (GTFs): TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH, each of which has a different role in regulating gene transcription. All GTFs are multi-subunit, except for TFIIB.
The GTFs are involved in the preinitiation complex (PIC) assembly which positions RNA polymerase II and separates the template strand at the transcription start site through a number of steps as outlined:
- TFIIA facilitates and stabilises TFIID binding to the TATA box.
- TFIID recruits the single subunit factor TFIIB.
- With this interaction, TFIIB recruits RNA polymerase II-TFIIF complex (TFIIF is joined toRNA polymerase II before this recruitment.)
- The recruitment of the RNA polymerase II-TFIIF allows TFIIE and then finally TFIIH to bind, completing the PIC assembly.
This is known as the classical pathway; not all promoters are turned on in this way.
Function of GTFs
TFIID: Binds to the TATA box, recruits TFIIB
TFIIA: Stabilizes TFIID binding, anti repression function
TFIIB: Recruits RNA pol II-TFIIF, important for start site selection
TFIIF: Stimulates elongation, destabilizes non specific RNA pol II-DNA interactions
TFIIE: Recruits TFIIH and modulates TFIIH activity
TFIIH: Promoter melting and clearance, CTD kinase activity, DNA repair coupling[1]
Reference
- ↑ Harvey L, Arnold B, Chris A, Monty K, Anthony B, Hidde P, Angelika A, Kelsey C, 2016, Molecular Cell Biology, 8th edition, New York: W. H. Freeman