title: IGSF9 family proteins.
abstract: The Drosophila protein Turtle and the vertebrate proteins immunoglobulin superfamily (IgSF), member 9 (IGSF9/Dasm1) and IGSF9B are members of an evolutionarily ancient protein family. A bioinformatics analysis of the protein family revealed that invertebrates contain only a single IGSF9 family gene, whereas vertebrates contain two to four genes. In cnidarians, the gene appears to encode a secreted protein, but transmembrane isoforms of the protein have also evolved, and in many species, alternative splicing facilitates the expression of both transmembrane and secreted isoforms. In most species, the longest isoforms of the proteins have the same general organization as the neural cell adhesion molecule family of cell adhesion molecule proteins, and like this family of proteins, IGSF9 family members are expressed in the nervous system. A review of the literature revealed that Drosophila Turtle facilitates homophilic cell adhesion. Moreover, IGSF9 family proteins have been implicated in the outgrowth and branching of neurites, axon guidance, synapse maturation, self-avoidance, and tiling. However, despite the few published studies on IGSF9 family proteins, reports on the functions of both Turtle and mammalian IGSF9 proteins are contradictory.
authors: Protein Laboratory, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, Panum Institute, University of Copenhagen, Building 24.2, Blegdamsvej 3, 2200 Copenhagen N, Denmark.
authors: Maria
authors: M
authors: Hansen
authors: Peter Schledermann
authors: PS
authors: Walmod
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry / Q000235:genetics*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D009369:Neoplasms / Q000503:physiopathology; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics*; D019006:Neural Cell Adhesion Molecules / Q000737:chemistry / Q000235:genetics*; D016501:Neurites / Q000502:physiology; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics; D011499:Protein Processing, Post-Translational; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; C486759:Igsf9 protein, mouse; D007136:Immunoglobulins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D019006:Neural Cell Adhesion Molecules; D020033:Protein Isoforms; C427323:tutl protein, Drosophila