PROTEIN-KINASE-C AND RECEPTOR KINASE GENE-EXPRESSION IN OLFACTORY RECEPTOR NEURONS

Recent biochemical evidence indicates that protein kinase C (PKC) and G-protein-coupled receptor kinases (GRKs) are involved in olfactory si gnal termination and desensitization. The polymerase chain reaction (P CR) was used to investigate the expression of PKC and GRK genes in olf actory tissue and in isolated olfactory receptor neurons from channel catfish (Ictalurus punctatus). Sequence analysis of cloned PKC PCR pro ducts showed that the alpha, beta, delta, epsilon, and theta isotypes were expressed in olfactory tissue, Sequence analysis of PCR products obtained from isolated olfactory receptor neurons showed that PKC beta and PKC delta were expressed in the receptor cells. A 600-bp GRK PCR product was obtained from isolated olfactory neurons that shared 86% a nd 92% amino acid sequence identity to the mammalian beta-adrenergic r eceptor kinase gene products beta ARK1 and beta ARK2, respectively. Go 6976, a specific inhibitor of calcium-regulated PKC activity, complete ly inhibited odorant-stimulated PKC activity in isolated olfactory cil ia, This result suggested that odorant-stimulated PKC activity is medi ated by the calcium-sensitive PKC beta isotype, Taken together, these results are consistent with the conclusion that PKC beta and beta ARK mediate odorant receptor phosphorylation and olfactory signal terminat ion. (C) 1997 John Wiley & Sons, Inc.