Cloning the 5' flanking region of neuron-specific Hel-N1: evidence for positive regulatory elements governing cell-specific transcription.
A 5.4 kilobase-pair segment of DNA flanking the 5' end of Hel-N1 was isolated and characterized. Primer extension studies with normal human brain and neuroblastoma cells revealed a major and minor transcription-initiation site. Sequence analysis of the initial 536 bp upstream to the major start site revealed a core promoter (-1 to -181) which contained two CCAAT boxes, a weakly-conserved TATA box, and an SP1 site. This region was also moderately GC-rich (62%). Using a transient luciferase-reporter-gene assay, the core promoter was found to be essential for basal transcription both in neural (PC12) and non-neural (HeLa and glial) cell types. Two positive regulatory elements, however, were identified in the initial 536 bp (-1 to -181 and -182 to -350) which produced a five- to six-fold increase in transcriptional activity in PC12 cells vs. HeLa or glial cells. These elements, therefore, were sufficient to confer cell-specific enhanced transcription and likely contribute to the neuronal specificity of Hel-N1 mRNA expression.
King
P H
PH
Department of Neurology, University of Alabama, Birmingham 35294-0007, USA. P_king@email.neuro.uab.edu
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D051959:ELAV Proteins; D000067777:ELAV-Like Protein 2; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics*; D051381:Rats; D014158:Transcription, Genetic / Q000235:genetics*
D051959:ELAV Proteins; D000067777:ELAV-Like Protein 2; C086811:ELAVL2 protein, human; C490170:Elavl2 protein, rat; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins