This proposal is aimed at learning the roles of the XPB and XPD subunits of the multi-protein factor TFIIH. TFIIH is essential for transcription of RNA, repair of DNA and control of cellular mitosis. XPB is essential to both transcription and repair and XPD is used for repair and mitotic control. 3 human diseases track to mutations in the XPB and XPD subunits, XP (xeroderma pigmentosum), CS (Cockaynes syndrome) and TTD (Trichothiodystrophy). TTD and CS are caused in significant part by transcription defects. There are major gaps in our knowledge of how these proteins function and how the mutated proteins contribute to CS and TTD. This proposal aims to fill those gaps. One goal is to determine how XPB leads to DNA opening during transcription. Binding and helicase assays using purified human components will be used to see how XPB and TFIIH cooperate with both basal transcription factors and activators to trigger appropriate promoter opening and transcription. In addition, mutations will be introduced into XPB in both human and fission yeast, and the effect on transcription and DNA repair determined within crude cellular extracts. Some of these mutations will mimic alleles that cause XPB diseases of transcription. A similar but less extensive analysis will be done with mutant XPD alleles. The role of other XP factors in facilitating communication between the transcription and DNA repair pathways will also be explored. These experiments are directed towards understanding whether there is an active mechanism for distributing TFIIH between transcription and DNA repair complexes. They will evaluate the roles of DNA repair factors known to bind transcription components by adding them to transcription extracts. How they interact with isolated transcription factors will also be explores to learn the extent of active communication between these 2 critical cellular processes.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM049048-12
Application #
7243374
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Tompkins, Laurie
Project Start
1994-05-01
Project End
2009-12-31
Budget Start
2007-07-01
Budget End
2009-12-31
Support Year
12
Fiscal Year
2007
Total Cost
$279,764
Indirect Cost
Name
University of California Los Angeles
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095