Increased calbindin-D28K immunoreactivity in rat cerebellar Purkinje cell with excitatory amino acids agonists is not dependent on protein synthesis.
The calcium binding protein Calbindin-D28K (CaBP) is abundantly expressed in cerebellar Purkinje cells and show increased immunoreactivity (CaBP-IR) when challenged with glutamate or an analog agonist for the ionotropic glutamate receptor (iGluR). Here we report that t-ACPD, a metabotropic glutamate receptor (mGluR) agonist, produced small increases in CaBP-IR which was potentiated by a mGluR antagonist The increase in CaBPIR was not due to de novo protein synthesis because the translational inhibitors (cycloheximide and emetine) or transciptional inhibitors (actinomycine-D and a-amanitine), did not prevent the EAA enhanced CaBP-IR. The CaBP-IR in the PC appears to be coupled to the ionotropic rather than the metabotropic glutamate receptors, but the latter become effective in the presence of their blocker, L-AP3. The results suggest that CaBP may increase its IR through a conformational change of the protein itself.
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Laboratoire de Physiologie de la Motricité, CNRS UMR 9923, Université Pierre et Marie Curie, 75634, CHU Pitié-Salpêtrière, Paris, France.
Kado
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Batini
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D000818:Animals; D064092:Calbindin 1; D064026:Calbindins; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism / Q000633:toxicity; D007150:Immunohistochemistry; D008297:Male; D009410:Nerve Degeneration / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D009498:Neurotoxins / Q000378:metabolism / Q000633:toxicity; D014176:Protein Biosynthesis / Q000187:drug effects / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011689:Purkinje Cells / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis* / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology*
C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D009498:Neurotoxins; D011500:Protein Synthesis Inhibitors; D018094:Receptors, Metabotropic Glutamate; D064030:S100 Calcium Binding Protein G; D018698:Glutamic Acid