title: Expression of the IgSF protein Kirre in the rat central nervous system.
abstract: OBJECTIVE
  Immunoglobulin superfamily (IgSF) proteins play a critical role in development of the nervous system. Here, a new member of IgSF gene family was cloned from rat brain, which was subsequently identified as rat homolog of Drosophila Kirre. This new molecule was named as rat Kirre (rKirre). We aimed to reveal the developmental expression of rKirre, both at mRNA and protein levels, in the central nervous system. The deduced amino acid sequence of rKirre showed a putative PDZ binding motif at the C-terminus, which provided a rationale for analyzing the co-localization of rKirre and post-synaptic density protein 95 (PSD-95) in cultured rat cortical neurons.
  
  
  METHODS
  cDNA library screening was used in the isolation of cDNA. Northern blotting and Western blotting were used to reveal the levels of rKirre expression. In situ hybridization and immuno-fluorescent staining were used to determine the localization of rKirre.
  
  
  RESULTS
  The rKirre gene was found to be highly expressed in the cerebrum, hippocampus, cerebellum, brain stem and spinal cord of adult rats. In parallel, the protein level of rKirre was also increased in a developing cerebral cortex. In cultured rat cortical neurons, the amount of rKirre was significantly increased during neuronal differentiation. Immuno-cytofluorescent staining indicated that rKirre was present along the neurites of cortical neurons, and was co-localized with PSD-95.
  
  
  CONCLUSIONS
  These results suggested that rKirre might play an essential role in neuronal differentiation and development in the central nervous system.
authors.affiliation: Laboratory of Molecular Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
authors.forename: Lingwei
authors.initials: L
authors.lastname: Kong
authors.forename: Roy C Y
authors.initials: RC
authors.lastname: Choi
authors.forename: Heidi Q
authors.initials: HQ
authors.lastname: Xie
authors.forename: Xidao
authors.initials: X
authors.lastname: Wang
authors.forename: Guangdun
authors.initials: G
authors.lastname: Peng
authors.forename: Zhiqin
authors.initials: Z
authors.lastname: Xie
authors.forename: Karl W K
authors.initials: KW
authors.lastname: Tsim
authors.forename: Naihe
authors.initials: N
authors.lastname: Jing
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002454:Cell Differentiation; D002478:Cells, Cultured; D002490:Central Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D000076122:Disks Large Homolog 4 Protein; D015723:Gene Library; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D054731:PDZ Domains; D051381:Rats; D017207:Rats, Sprague-Dawley; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; C486607:Kirrel1 protein, rat; D008565:Membrane Proteins