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Title: Identification and purification of a novel 120-kDa protein that recognizes the cAMP-responsive element

The TGACGTCA (CRE) motif required for function by a number of cellular (somatostatin, enkephalin, alpha-human chorionic gonadotropin) and viral (Ad5 E1A-inducible, HTLV-1 TAX-inducible) genes is the site of interaction of multiple sequence-specific complexes. A protocol has been developed for the fractionation and purification of these activities. We report here the purification from HeLa nuclear extracts of a novel 120-kDa polypeptide which by Southwestern blots, gel retardation, and UV cross-linking assays displays CRE-specific binding. The CRE-affinity purified 120-kDa protein displays properties distinct from those of the 43-kDa CREB/ATF polypeptide. The 120-kDa protein is readily phosphorylated in vitro by protein kinase C but not by protein kinase A, suggesting that this molecule may mediate cellular signals distinct from the cAMP-responsive pathway. In vitro transcription-complementation assays utilizing the purified 120-kDa protein failed to transactivate the cAMP-responsive somatostatin promoter suggesting that the mode of action of this 120-kDa polypeptide may require an activation step distinct from the cAMP-signaling pathway.
Authors:
;  [1]
  1. (Purdue Univ., West Lafayette, IN (USA))
Publication Date:
OSTI Identifier:
7025539
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Biological Chemistry; (USA); Journal Volume: 265:6
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; POLYPEPTIDES; FRACTIONATION; BIOCHEMICAL REACTION KINETICS; BIOLOGICAL PATHWAYS; CELL NUCLEI; CHEMICAL RADIATION EFFECTS; CHROMATOGRAPHY; CROSS-LINKING; ELECTROPHORESIS; HELA CELLS; MOLECULAR WEIGHT; OLIGONUCLEOTIDES; PHOSPHORYLATION; PHOSPHOTRANSFERASES; TRANSCRIPTION; ULTRAVIOLET RADIATION; CELL CONSTITUENTS; CHEMICAL REACTIONS; CHEMISTRY; ELECTROMAGNETIC RADIATION; ENZYMES; KINETICS; NUCLEIC ACIDS; ORGANIC COMPOUNDS; PEPTIDES; PHOSPHORUS-GROUP TRANSFERASES; POLYMERIZATION; PROTEINS; RADIATION CHEMISTRY; RADIATION EFFECTS; RADIATIONS; REACTION KINETICS; SEPARATION PROCESSES; TRANSFERASES 560120* -- Radiation Effects on Biochemicals, Cells, & Tissue Culture