Transcription factor: Difference between revisions
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#TFIIA facilitates and stabilises TFIID binding to the [[TATA box|TATA box]]. | #TFIIA facilitates and stabilises TFIID binding to the [[TATA box|TATA box]]. | ||
#TFIID recruits the single subunit factor TFIIB. | #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]] | #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. | #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 | 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 === | |||
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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 TFIIBTFIIA: Stabilizes TFIID binding, anti repression functionTFIIB: Recruits RNA pol II-TFIIF, important for start site selectionTFIIF: Stimulates elongation, destabilizes non specific RNA pol II-DNA interactionsTFIIE: Recruits TFIIH and modulates TFIIH activityTFIIH: 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