Mutually dependent response elements in the cis-regulatory region of the neurotensin/neuromedin N gene integrate environmental stimuli in PC12 cells.
The expression of the gene encoding the neuroendocrine peptides neurotensin (NT) and neuromedin N is strictly dependent on simultaneous exposure to multiple inducers in PC12 pheochromocytoma cells. NT peptide and NT/N mRNA levels are synergistically induced by combinations of NGF, dexamethasone, activators of adenylate cyclase, and lithium ion. We have used transient transfection assays to delineate the rat NT/N gene sequences necessary for this complex regulation. Progressive deletions of the 5' flanking region revealed that sequences between -216 and +56 are sufficient to confer the full spectrum of responses exhibited by the endogenous gene to a reporter gene. Detailed mutational analysis of this region indicates that it is composed of an array of inducible cis-regulatory sequences, including AP-1, cAMP response, and glucocorticoid response elements. Specific mutation of either the AP-1 site or each of two cAMP response elements indicates that they are functionally interdependent. This array of response elements serves to integrate multiple environmental stimuli into a unified transcriptional response.
Kislauskis
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Department of Molecular Genetics and Microbiology, University of Massachusetts Medical Center, Worcester 01655.
Dobner
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PR
D000310:Adrenal Gland Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D005809:Genes, Regulator / Q000502:physiology*; D008969:Molecular Sequence Data; D009496:Neurotensin / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D010446:Peptide Fragments / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D010641:Phenotype; D010673:Pheochromocytoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology; D051381:Rats; D014407:Tumor Cells, Cultured / Q000473:pathology*
D010446:Peptide Fragments; C042090:neuromedin N; D009496:Neurotensin