PROMOTER REGION OF THE TRANSCRIPTIONAL UNIT FOR HUMAN ALPHA-1-CHIMAERIN, A NEURON-SPECIFIC GTPASE-ACTIVATING PROTEIN FOR P21RAC.
EUR J BIOCHEM
636 - 646.
alpha 1-chimaerin is a neuron-specific GTPase-activating protein for p21rac, a protein involved in morphological events. The mRNA is highly expressed in certain brain regions. It is also detected in cultured neuronal, but not in non neuronal cells. As a first step towards understanding the mechanisms underlying this regulation, genomic clones containing the 5'-flanking region of the human alpha 1-chimaerin transcriptional unit were isolated and characterised. A cluster of multiple transcription start sites of alpha 1-chimaerin mRNAs was detected by primer-extension and S1-mapping analyses. The cluster was mapped to nucleotides -463 to -434 (relative to nucleotide A in the initiation codon) in genomic DNA. The 5'-proximal region contained no TATA box, initiator motif and Sp1-binding site. A 210-bp fragment with approximately 110 bp 5'-flanking sequence could function as a minimal promoter upon analysis using hybrid chloramphenicol acetyltransferase reporter constructs and transient transfection. Internal deletion and point-mutation experiments revealed that a GGCCAATC sequence located at nucleotides -519 to -512 was essential for alpha 1-chimaerin promoter activity. Mobility-shift assay showed the specific binding of nuclear factor(s) to this region, which was competed by the oligonucleotides corresponding to wild-type but not mutant forms. The data also suggest the existence of possible novel CCAAT-binding factor(s) interacting with the alpha 1-chimaerin CCAAT box binding site. A cell-type-preferred suppressor located in the 5'-distal region was found which may play a role in controlling neuron-specific expression of alpha 1-chimaerin mRNA. These findings of a specific promoter for alpha 1-chimaerin transcription will facilitate further studies on its neuronal specific expression and function.
|Title:||PROMOTER REGION OF THE TRANSCRIPTIONAL UNIT FOR HUMAN ALPHA-1-CHIMAERIN, A NEURON-SPECIFIC GTPASE-ACTIVATING PROTEIN FOR P21RAC|
|Keywords:||CHIMAERIN, PROMOTER ANALYSIS, NEURONAL GENE EXPRESSION, CCAAT-BINDING PROTEIN, CAT VECTORS, ADHESION MOLECULE GENE, SYNAPSIN-I GENE, BINDING-PROTEIN, REGULATORY ELEMENTS, SILENCER ELEMENT, N-CHIMAERIN, EXPRESSION, P21RAC, RNA, IDENTIFICATION|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Neurology|
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