The relationship between the general transcription factor TFIIF and Gdown1 in promoter proximal pausing and the properties of TFIIFs truncated versions 1-217 and 1-356 within that relationship
File(s)
Author(s)
Axson, EL
Mullen-Davis, MA
Luse, DS
Type
Poster
Abstract
RNA Polymerase II (Pol II) requires several additional factors, known as general transcription factors (GTFs), to recognise promoters and initiate the synthesis of pre-mRNA. It is now appreciated that a post-initiation step, involving extended pausing of Pol II at ~50 base pairs downstream of transcription start, is also a key regulatory step in gene expression. It is not well understood how the GTFs relate to the factors that control this pausing. Of particular interest, is the relationship between one GTF, TFIIF, and one of the pausing factors, Gdown1. Gdown1 associates very tightly with Pol II and it can be thought of as a 13th, substoichiometric subunit of polymerase. Surprisingly, Gdown1 shares binding sites on Pol II with TFIIF, blocks TFIIF association with free Pol II, and displaced TFIIF from Pol II during transcript elongation. An important question thus arises: How can transcription begin if a factor necessary in pausing blocks the association of a factor necessary for transcription to start? Here I show, using a well-characterized in vitro transcription system: 1) that once a pol II pre-initiation complex (PIC) is formed, Gdown1 cannot displace TFIIF from it and 2) that the truncated versions of TFIIF are less effective at rescuing transcription than full length TFIIF.
Date Issued
2013-08-15
Online Publication Date
2013-08-15
2017-11-06T11:06:08Z
Copyright Statement
© 2013 The Author(s)
Source Database
manual-entry
Subjects
RNA
Transcription