Analysis of promoter activity and 5? genomic structure of the neural cell adhesion molecule L1 (original) (raw)

1992, Journal of Neuroscience Research

To gain insight into the molecular mechanisms underlying the regulation of expression of the neural cell adhesion molecule L1 and into the exon-intron structure of the L1 gene, a genomic clone from the mouse was characterized. The clone was identified by screening an EMBL3 library with an L1-specific cDNA probe and comprises approximately 15 kb, in which the first 2,206 nucleotides of the coding region are included. Of the 5 of 6 immunoglobulin (1g)-like domains sequenced, all are encoded by 2 exons, with the first exon being smaller than the second. The exon encoding the signal peptide is separated from a miniexon containing 15 bp by a large intron, approximately 2.6 kb in length, whereas the other introns are smaller, with the coding information for the Ig-like domains 3-5 clustered in a 1,643-bp-long fragment with introns only 110-217 bp in length. The 5' upstream region of the clone comprises 5 kb, with the first 112 bp lying upstream to the coding sequence and containing a start site for transcription. No consensus sequence for a TATA box was found. Consensus DNA sequences for the binding of the gene products of Hox 1.3, engrailed and bicoid, are localized upstream to the transcription start site. A 1,262-bp fragment containing part of the first exon showed promoter activity in neuroblastoma cells, but hardly in L cells and not in CHO cells, indicating that this fragment is sufficient for neural cell directed promoter activity. Atashi JR, Ingraham CAT Klinz SG, Matten WT, Schachner M (1992): Neural cell adhesion molecules modulate tyrosine phosphorylation of tubulin in nerve growth membranes. Neuron, in press. Augereau P, Chambon P (1986): The mouse immunoglobulin heavychain enhancer: Effect on transcription in vitro and binding of proteins present in HeLa and lymphoid B cell extracts. EMBO Barbas JA, Chaix J-C, Steinmetz M, Goridis C (1988): Differential splicing and alternative polyadenylation generates distinct N-CAM transcripts and proteins in the mouse. EMBO J 7:625-632. Biggin MD, Tjian R (1989): Transcription factors and the control of Drosophila development. Trends Genet 5:37Y -385. Blumberg B, Wright CVE, De Robertis EM, Cho KWY (1991): Organizer-specific homeobox genes in Xenopus laevis embryos. Science 253:194-195. Bock E, Richter-Landsberg C, Faissner A, Schachner M (1985): Demonstration of immunochemical identity between the nerve growth factor-inducible large external (NILE) glycoprotein and the cell adhesion molecule L1. EMBO J 4:2765-2768. Bradford MM (1976): A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of proteindye binding. Anal Biochem 72:248-254. Burgoon MP, Grumet M, Mauro V, Edelman GM, Cunningham BA (1991): Structure of the chicken neuron-glia cell adhesion molecule, Ng-CAM: Origin of the polypeptides and relation to the Ig superfamily.