The Human TAX1 Gene Encoding the Axon-Associated Cell Adhesion Molecule TAG-1/Axonin-1: Genomic Structure and Basic Promoter

• Published in: Genomics (San Diego, Calif.) Calif.), 1995-11, Vol.30 (2), p.141-148
• Main Authors: Kozlov, Serguei V., Giger, Roman J., Hasler, Thomas, Korvatska, Elena, Schorderet, Daniel F., Sonderegger, Peter
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Biological and medical sciences; Cell Adhesion Molecules, Neuronal - genetics; Chickens; Chromosome Mapping; Cloning, Molecular; Contactin 2; Exons; Fundamental and applied biological sciences. Psychology; Genes, Reporter; Genes. Genome; Humans; Introns; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Promoter Regions, Genetic; Repetitive Sequences, Nucleic Acid; Sequence Homology, Nucleic Acid
• ISSN: 0888-7543; 1089-8646
• DOI: 10.1006/geno.1995.9892

The human TAX-1 gene (HGMW-approved symbol TAX1) is located on chromosome 1 (1q32.1) and encodes the neuronal cell adhesion molecule TAG-1/axonin-1. The gene product, termed TAG-1 in the rat and axonin-1 in the chicken, is composed of six immunoglobulin (Ig)-like and four fibronectin type III (FNIII)-like domains. It is found predominantly on the axons of particular nerve fiber tracts during neural development, and it has been demonstrated to function as a potent substratum for neurite outgrowthin vitro.Here we report the cloning and structural characterization of the TAX-1 gene. The transcribed region of the TAX-1 gene extends over about 40 kb. Like its chicken homologue, the human TAX-1 gene consists of 23 exons. Two GT/CA microsatellites were localized in the first intron; a polymorphism was found for one of them. Reporter gene analysis with serially truncated fragments of the 5′-flanking region indicated that a 164-bp fragment located immediately upstream of the putative transcription initiation site was sufficient to function as a basal promoter.