Sequences required for induction of neurotensin receptor gene expression during neuronal differentiation of N1E-115 neuroblastoma cells.
The promoter region of the mouse high affinity neurotensin receptor (Ntr-1) gene was characterized, and sequences required for expression in neuroblastoma cell lines that express high affinity NT-binding sites were characterized. Me(2)SO-induced neuronal differentiation of N1E-115 neuroblastoma cells increased both the expression of the endogenous Ntr-1 gene and reporter genes driven by NTR-1 promoter sequences by 3-4-fold. Deletion analysis revealed that an 83-base pair promoter region containing the transcriptional start site is required for Me(2)SO activation. Detailed mutational analysis of this region revealed that a CACCC box and the central region of a large GC-rich palindrome are the crucial cis-regulatory elements required for Me(2)SO induction. The CACCC box is bound by at least one factor that is induced upon Me(2)SO treatment of N1E-115 cells. The Me(2)SO effect was found to be both selective and cell type-restricted. Basal expression in the neuroblastoma cell lines required a distinct set of sequences, including an Sp1-like sequence, and a sequence resembling an NGFI-A-binding site; however, a more distal 5' sequence was found to repress basal activity in N1E-115 cells. These results provide evidence that Ntr-1 gene regulation involves both positive and negative regulatory elements located in the 5'-flanking region and that Ntr-1 gene activation involves the coordinate activation or induction of several factors, including a CACCC box binding complex.
Tavares
D
D
Department of Molecular Genetics, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
Tully
K
K
Dobner
P R
PR
D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D003001:Cloning, Molecular; D004247:DNA; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D051379:Mice; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000166:cytology*; D011401:Promoter Regions, Genetic; D018028:Receptors, Neurotensin / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D018028:Receptors, Neurotensin; D004247:DNA; D004121:Dimethyl Sulfoxide