R A North

..The mechanosensitive channel of bacteria has emerged as the simplest form of a channel protein subunit with two hydrophobic domains...

..Recent studies suggest that it is important to use purified nucleotides in such classifications. Several P2Y receptors have a very widespread tissue distribution...

..The functional properties and tissue distribution of these six P2X receptors indicate new roles for ATP-gated ion channels...

..Thus, the P2X7 (or P2Z) receptor is a bifunctional molecule that could function in both fast synaptic transmission and the ATP-mediated lysis of antigen-presenting cells...

..They also introduce a new phenotype for ATP responses at P2X receptors--insensitivity to currently known antagonists...

..Although in some tissues responses to ATP can be accounted for by homomeric channels, our results indicate that ATP-gated channels of sensory neurons may form by a specific heteropolymerization of P2X receptor subunits...

..The present results show that a "per-subunit" channel block causes the blocking effects of MTSET and they suggest that not four but maximally three subunits actively participate in the channel formation...

..Expression of chimeric molecules indicated that some of the differences between the rat and human receptor could be reversed by exchanging the intracellular C-terminal domain of the proteins...

..Thus, calmidazolium can block activation of the ionic channel but this does not prevent the formation of the large permeabilizing pore...

..3 nM) but not to orphanin FQ. Thus, both kappa and orphanin FQ receptors readily couple to potassium channels, but the highly selective activation by dynorphin and orphanin FQ is consistent with distinct functional pathways in vivo...

..The correspondence in properties between P2X2/3 receptors and nodose ganglion neurones further supports the conclusion that the native alpha,beta-methylene ATP-sensitive receptor is a P2X2/3 heteromultimer...

..Additional sequences with the duplicate pore motif were found in C. elegans, suggesting that these proteins represent a novel structural family of potassium channel proteins...

..5. It is proposed that lanthanum, gadolinium and barium can usefully separate these endogenous membrane currents in Xenopus oocytes...

..The P2x receptor thus defines a new family of ligand-gated ion channels...

..Others, such as RPTPbeta, might exert feedback control of the channel itself through its dephosphorylation...

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..The results suggest that Val(48) at the outer end of the first hydrophobic segment takes part in the gating movement of channel opening...

..We conclude that microvesicle shedding is a major secretory pathway for rapid IL-1beta release from activated monocytes and may represent a more general mechanism for secretion of similar leaderless secretory proteins...

..P2X receptors mediating fast synaptic excitation are predominately P2X2 homomeric receptors...

..The current nomenclature is based largely on recombinant receptor studies and detailed knowledge of endogenous P2X receptors in native tissues is limited because of lack of good selective agonists and antagonists for each receptor type...

..The molecular characterization of this receptor should lead to a better understanding of the functional role of this important family of hormone receptors in adult organisms and during development...

..These results demonstrate that domains of these transporters can function in chimeric combinations to control viral receptor and transport functions...

..These observations demonstrate that the tachykinin family of peptide transmitters and their receptors represent an evolutionarily ancient form of cellular communication within the nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)..

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..This pattern contrasts with the exclusive peripheral expression of a recently cloned human SRIF receptor. The cDNA probe of rat receptor detects mRNA from mouse brain but not from human cerebral cortex and cerebellum...

..Activation of P2X receptors on macrophages is an important stimulus for cytokine release. This study seeks evidence for functional expression of P2X receptors in macrophages that had been only minimally activated...