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Nischarin as a functional imidazoline (I 1 ) receptor
Author(s) -
Zhang Jian,
Abdel-Rahman Abdel A.
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2006.04.058
Subject(s) - receptor , signal transduction , biology , microbiology and biotechnology , transfection , gene , biochemistry
Gene matching shows that Nischarin is a mouse homologue of human imidazoline receptor antisera‐selective (IRAS) protein, a viable candidate of the imidazoline (I 1 ) receptor. Nischarin and IRAS share the functions of enhancing cell survival, growth and migration. Bioinformatics modeling indicates that the IRAS and Nischarin may be transmembrane proteins and the convergence information raises the interesting possibility that Nischarin might serve as the I 1 ‐receptor. To test this hypothesis, we developed antibodies against the Nischarin protein, and conducted signal transduction (functional) studies with the I 1 ‐receptor agonist rilmenidine in the presence and absence of Nischarin antisense oligodeoxynucleotides (ODNs). NIH3T3 cells transfected with the Nischarin cDNA and incubated with the newly synthesized antibody expressed a 190 kD band. The antibody identified endogenous Nischarin in differentiated PC12 cells around 210 kD, which is consistent with reported findings in other cells of neuronal origin. The immunoflourescence findings showed the targeted protein to be associated with the cell membrane in PC12 cells. Nischarin ODNs abolished the expression of Nischarin in PC12 cells. Equally important, the Nischarin ODNs eliminated the production of MAPK p42/44 , a recognized signal transduction product generated by I 1 ‐receptor activation in differentiated PC12 cells. Together, the present findings suggest that Nischarin may serve as the functional I 1 ‐receptor or at least share a common signaling pathway in the differentiated PC12 cells.