The overall goal of the research described here is to understand the mechanisms used by the cAMP response element binding protein, CREB, to regulate gene transcription in the basal state and in response to signals generate by stimulation of cells with hormones and neurotransmitters. These extracellular signals activate a variety of protein kinases that phosphorylate Ser 133 in the kinase inducible domain (KID) of CREB and enhance transcription activation. In order to stimulate transcription of a target gene, it is necessary to: 1) recruit a polymerase complex to the promoter; 2) isomerize the polymerase complex to an active state capable of melting the DNA template in an ATP-dependent process; and 3) dissemble the polymerase complex to allow the polymerase to assume its stable elongating conformation in a step called promoter clearance. All of these steps can be regulated by interactions between transcription factors and the polymerase complex. In the previous cycle of this grant, we showed that the constitutive activation domain (CAD) in CREB is necessary and sufficient to mediate recruitment of a polymerase complex through interaction with the promoter recognition factor IID, and that phosphorylation of the KID in CREB stimulates the activity of this complex to facilitate subsequent steps in transcription initiation. We hypothesize that P-CREB enhances isomerization and promoter clearance by regulating the recruitment and activation of IIg and that reinitiation is primarily a recruitment phenomenon, although it could be augmented by phosphorylation of CREB. The studies described here are designed to determine: 1) which post-recruitment steps in the transcription reaction are regulated by the phospho-CREB(P-CREB); 2) which general transcription factors are required for stimulation of each of these steps; and 3) how the general factors interact, whether directly or indirectly, with P-CREB or its co- activators. This is an important question because virtually all cells and tissues rely upon some form of signaling to CREB, whether to regulate metabolite processes, growth and development of endocrine tissues, or maturation and survival of neurons. It is probable that at least some of the features of the transcription activation pathway we elucidate for P- CREB will be shared by other transcription factors regulated by different hormones.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK043871-14
Application #
6896099
Study Section
Endocrinology Study Section (END)
Program Officer
Margolis, Ronald N
Project Start
1991-05-01
Project End
2007-06-30
Budget Start
2005-07-01
Budget End
2007-06-30
Support Year
14
Fiscal Year
2005
Total Cost
$264,160
Indirect Cost
Name
Pennsylvania State University
Department
Physiology
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Quinn, P G; Yeagley, D (2005) Insulin regulation of PEPCK gene expression: a model for rapid and reversible modulation. Curr Drug Targets Immune Endocr Metabol Disord 5:423-37
Felinski, E A; Quinn, P G (2001) The coactivator dTAF(II)110/hTAF(II)135 is sufficient to recruit a polymerase complex and activate basal transcription mediated by CREB. Proc Natl Acad Sci U S A 98:13078-83
Felinski, E A; Kim, J; Lu, J et al. (2001) Recruitment of an RNA polymerase II complex is mediated by the constitutive activation domain in CREB, independently of CREB phosphorylation. Mol Cell Biol 21:1001-10
Kim, J; Lu, J; Quinn, P G (2000) Distinct cAMP response element-binding protein (CREB) domains stimulate different steps in a concerted mechanism of transcription activation. Proc Natl Acad Sci U S A 97:11292-6
Budworth, P R; Quinn, P G; Nilson, J H (1997) Multiple characteristics of a pentameric regulatory array endow the human alpha-subunit glycoprotein hormone promoter with trophoblast specificity and maximal activity. Mol Endocrinol 11:1669-80
Xing, L; Gopal, V K; Quinn, P G (1995) cAMP response element-binding protein (CREB) interacts with transcription factors IIB and IID. J Biol Chem 270:17488-93
Quinn, P G (1994) Inhibition by insulin of protein kinase A-induced transcription of the phosphoenolpyruvate carboxykinase gene. Mediation by the activation domain of cAMP response element-binding protein (CREB) and factors bound to the TATA box. J Biol Chem 269:14375-8
Xing, L; Quinn, P G (1994) Three distinct regions within the constitutive activation domain of cAMP regulatory element-binding protein (CREB) are required for transcription activation. J Biol Chem 269:28732-6
Quinn, P G (1993) Distinct activation domains within cAMP response element-binding protein (CREB) mediate basal and cAMP-stimulated transcription. J Biol Chem 268:16999-7009
Xing, L; Quinn, P G (1993) Involvement of 3',5'-cyclic adenosine monophosphate regulatory element binding protein (CREB) in both basal and hormone-mediated expression of the phosphoenolpyruvate carboxykinase (PEPCK) gene. Mol Endocrinol 7:1484-94