title: Characterization of the genomic structure of the mouse limbic system-associated membrane protein (Lsamp) gene.
abstract: The Lsamp gene encodes the limbic system-associated membrane protein (LAMP) an immunoglobulin (Ig) superfamily member with three Ig domains and a glycosylphosphatidylinositol anchor. LAMP is expressed by neurons composing the limbic system, is highly conserved between rodents and human, and has structural and functional properties that substantiate its role in the formation of limbic circuits. We report here the genomic organization of the Lsamp gene. The Lsamp gene is composed of 11 exons distributed over 2.2 megabases (Mb). Two exons 1 are separated by approximately 1.6 Mb and contribute to the unusual large size of the gene. Alternative spliced Lsamp mRNAs are generated from distinct promoter regions associated with the two exons 1 that encode distinct signal peptides and thus generate identical native mature polypetides. Additional diversity is created by the use of two small exons to include an insertion of 23 amino acids within the polypeptide C-terminal region of the mature protein. The genomic features of the Lsamp gene described here indicate an intricate mechanism of gene expression regulation that may be relevant in the context of human neuropsychiatric and neurological disorders, where LAMP expression may be altered.
authors.affiliation: John F. Kennedy Center for Research on Human Development and Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA. aurea.pimenta@vanderbilt.edu
authors.forename: Aurea F
authors.initials: AF
authors.lastname: Pimenta
authors.forename: Pat
authors.initials: P
authors.lastname: Levitt
mesh_terms: D017398:Alternative Splicing / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015816:Cell Adhesion Molecules, Neuronal / Q000737:chemistry / Q000235:genetics*; D005091:Exons / Q000235:genetics; D058851:GPI-Linked Proteins; D023281:Genomics; D006801:Humans; D007438:Introns / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D058851:GPI-Linked Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; C095362:limbic system-associated membrane protein