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Characterization of a cAMP-regulated enhancer-binding protein
J F Habener1, T E Meyer, Y Yun
1Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Boston 02114.
Metabolism: Clinical and Experimental
|September 1, 1990
Summary
The cAMP response element binding protein (CREB) regulates hormone gene transcription by binding to specific DNA sequences. Phosphorylation by protein kinase A activates CREB, influencing gene expression.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Intracellular cyclic AMP (cAMP) modulates transcription of numerous hormone genes.
- The cAMP response element (CRE) is an 8-base pair enhancer (TGACGTCA) in gene 5'-flanks, recognized by CREB.
Purpose of the Study:
- To characterize the CREB family of transcription factors.
- To understand the molecular mechanisms of CREB-mediated gene regulation.
Main Methods:
- cDNA cloning and characterization
- Southwestern blot analysis
- Northern blot analysis
Main Results:
- CREB and related proteins form a family of transcription factors.
- These factors dimerize via a leucine zipper motif.
- They bind to the CRE through positively charged basic regions.
- CREB (327 residues) is activated by phosphorylation, notably by cAMP-dependent protein kinase A.
Conclusions:
- CREB is a key regulator of hormone gene transcription.
- Phosphorylation is a critical mechanism for CREB activation.
- The structural features of CREB facilitate DNA binding and dimerization.