title: Distribution of RA175/TSLC1/SynCAM, a member of the immunoglobulin superfamily, in the developing nervous system.
abstract: RA175 is a new member of the immunoglobulin superfamily with trans interaction activity, and it plays a role as a tumor suppressor in lung carcinoma (TSLC1) and as a cell adhesion molecule promoting the formation of functional synapses (SynCAM). Little is known about the biological function of RA175/TSLC1/SynCAM neural network formation during neurogenesis. We examined the distribution and colocalization of the RA175/TSLC1/SynCAM protein with other members of the immunoglobulin superfamily such as NCAM, L1, and TAG-1 in the mouse developing nervous system. Consistent with the expression of RA175/TSLC1/SynCAM mRNA, the protein was localized in the brain neuroepithelium at embryonic day (E) 9.5, neural crest at E10.5, motor neurons at E10.5, and olfactory epithelium at E16.5. In contrast with its mRNA, the protein was intensely detected on the fasciculated axons in the floor plates, ventral root, and dorsal funiculus in the E10.5-11.5 spinal cord and colocalized with NCAM and L1 on the ventral root and dorsal funiculus and partly colocalized with TAG-1 on the commissural axons and dorsal funiculus. In the E13.5-15.5 brain, RA175/TSLC1/SynCAM colocalized with NCAM and L1 on the developing thalamocortical fibers from the internal capsule (IC) and partly colocalized with TAG-1 on the cortical efferent axons in the intermediate zone (IZ). RA175/TSLC1/SynCAM was localized on the axons of some of the cortical neurons cultured in vitro. Thus, in addition to cell adhesion activity in the neuroepithelium and the synapses, RA175/TSLC1/SynCAM may be involved in neuronal migration, axon growth, pathfinding, and fasciculation on the axons of differentiating neurons.
authors.affiliation: Division of Development and Differentiation, National Institute of Neuroscience, NCNP, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Fujita
authors.forename: Koko
authors.initials: K
authors.lastname: Urase
authors.forename: Akiko
authors.initials: A
authors.lastname: Soyama
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Kouroku
authors.forename: Takashi
authors.initials: T
authors.lastname: Momoi
mesh_terms: D000818:Animals; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D058969:Contactin 2; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007136:Immunoglobulins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D007908:Lens, Crystalline / Q000196:embryology / Q000378:metabolism; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009420:Nervous System / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009831:Olfactory Mucosa / Q000196:embryology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D025521:Tumor Suppressor Proteins; D016875:tau Proteins / Q000378:metabolism
chemical_list: C498598:Cadm1 protein, mouse; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; C548675:Cntn2 protein, mouse; D058969:Contactin 2; D005904:Glial Fibrillary Acidic Protein; D007136:Immunoglobulins; D039841:Leukocyte L1 Antigen Complex; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; C079240:Mtap2 protein, mouse; D019006:Neural Cell Adhesion Molecules; D012333:RNA, Messenger; D014404:Tubulin; D025521:Tumor Suppressor Proteins; C462941:beta3 tubulin, mouse; D016875:tau Proteins