Competitive antagonism by phenylglycine derivatives at type I metabotropic glutamate receptors.

The metabotropic glutamate receptors (mGluRs) form a family of G-protein-coupled receptors which consists of at least seven members termed mGluR1-mGluR7. These members are classified into subfamilies according to their sequence similarities, signal transduction mechanisms and agonist selectivities. mGluR1 and mGluR5 are coupled to the phosphoinositide hydrolysis/Ca2+ signal transduction and efficiently respond to quisqualate.

Transcriptional activity of the neuron-specific enolase (NSE) promoter in murine embryonic stem (ES) cells and preimplantation embryos.

Mouse embryonic stem (ES) cells were transfected with a plasmid composed of an E. coli lacZ gene fused to 1.8 kb of rat neuron-specific enolase (NSE) promoter sequences.

Signal transduction mechanisms of recombinant bovine neurokinin-2 receptor stably expressed in baby hamster kidney cells.

The bovine neurokinin-2 (NK-2) receptor gene was stably transfected into Baby hamster kidney (BHK-21) fibroblasts and one recombinant clone expressing 17,700 high-affinity [125I]neurokinin A (NKA) binding sites/cell characterized further. [125I]NKA binding was displaced by unlabeled NKA with an IC50 of 8.26 +/- 2 nM (n = 5) and with the rank order of potency NKA > neurokinin B (NKB) > Substance P (SP) confirming pharmacological characteristics of an NK-2 receptor subtype.

Functional characterization of neurokinin-1 receptors on human U373MG astrocytoma cells.

The neurokinin-1 (NK-1, substance P) receptor belongs to the class of seven transmembrane domain (7-TM) receptors that interact with cellular effector systems via guanine nucleotide binding regulatory proteins (G-proteins). In this study, coupling mechanisms of functional NK-1 receptors endogenously expressed in a human astrocytoma cell line (U373MG) were analyzed. Stimulation with substance P (SP) resulted in 1) a rapid increase in inositol 1,4,5-trisphosphate (IP3) synthesis; 2) a rise in cytosolic free calcium concentration ([Ca2+]i); 3) induction of immediate early gene transcription as monitored by c-fos and c-jun expression; and 4) a significant increase in de novo DNA synthesis.

Recombinant bovine neurokinin-2 receptor stably expressed in Chinese hamster ovary cells couples to multiple signal transduction pathways.

Neurokinins are a family of neuropeptides with widespread distribution mediating a broad spectrum of physiological actions through three distinct receptor subtypes: NK-1, NK-2, and NK-3. We investigated some of the second messenger and cellular processes under control by the recombinant bovine NK-2 receptor stably expressed in Chinese hamster ovary cells. In this system the NK-2 receptor displays its expected pharmacological characteristics, and the physiological agonist neurokinin A stimulates several cellular responses.