title: Sema4c, a transmembrane semaphorin, interacts with a post-synaptic density protein, PSD-95.
abstract: Semaphorins are known to act as chemorepulsive molecules that guide axons during neural development. Sema4C, a group 4 semaphorin, is a transmembrane semaphorin of unknown function. The cytoplasmic domain of Sema4C contains a proline-rich region that may interact with some signaling proteins. In this study, we demonstrate that Sema4C is enriched in the adult mouse brain and associated with PSD-95 isoforms containing PDZ (PSD-95/DLG/ZO-1) domains, such as PSD-95/SAP90, PSD-93/chapsin110, and SAP97/DLG-1, which are concentrated in the post-synaptic density of the brain. In the neocortex, S4C is enriched in the synaptic vesicle fraction and Triton X-100 insoluble post-synaptic density fraction. Immunostaining for Sema4C overlaps that for PSD-95 in superficial layers I-IV of the neocortex. In neocortical culture, S4C is colocalized with PSD-95 in neurons, with a dot-like pattern along the neurites. Sema4C thus may function in the cortical neurons as a bi-directional transmembrane ligand through interacting with PSD-95.
authors.affiliation: Group of Neurobiology, School of Allied Health Sciences, Osaka University Faculty of Medicine, Yamadaoka 1-7, Suita-shi, Osaka, 565-0871, Japan. inagaki@sahs.med.osaka-u.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Inagaki
authors.forename: Y
authors.initials: Y
authors.lastname: Ohoka
authors.forename: H
authors.initials: H
authors.lastname: Sugimoto
authors.forename: S
authors.initials: S
authors.lastname: Fujioka
authors.forename: M
authors.initials: M
authors.lastname: Amazaki
authors.forename: H
authors.initials: H
authors.lastname: Kurinami
authors.forename: N
authors.initials: N
authors.lastname: Miyazaki
authors.forename: M
authors.initials: M
authors.lastname: Tohyama
authors.forename: T
authors.initials: T
authors.lastname: Furuyama
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002540:Cerebral Cortex / Q000378:metabolism; D017931:DNA Primers; D000076122:Disks Large Homolog 4 Protein; D018507:Gene Expression Regulation, Developmental; D051528:Guanylate Kinases; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D039961:Semaphorins; D013347:Subcellular Fractions / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D017931:DNA Primers; D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C501451:Mpp2 protein, rat; D009419:Nerve Tissue Proteins; C119353:Sema4c protein, mouse; D039961:Semaphorins; C033652:postsynaptic density proteins; C501445:Dlg2 protein, mouse; D051528:Guanylate Kinases