Accession Number : ADA267121


Title :   Modulation of Ionic Channel Function by Protein Phosphorylation


Descriptive Note : Final rept. 15 Mar 89-14 Oct 92,


Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF BIOLOGY


Personal Author(s) : Montal, Mauricio


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a267121.pdf


Report Date : 12 Nov 1992


Pagination or Media Count : 55


Abstract : Protein phosphorylation is considered a key event in synaptic physiology. The acetylcholine receptor (AChR), a prototype of ligand-gated ion channels, plays a central role in postsynaptic signal transduction. To examine the functional consequences of AChR phosphorylation, single-channel properties of purified Torpedo californica AChR reconstituted in planar lipid bilayers, were evaluated before and after phosphorylation by purified protein-serine and - tyrosine kinases, or dephosphorylation by recombinant protein tyrosine phosphatase. Single-channel conductance was not altered by changing the AChR serine or tyrosine phosphorylation state. In contrast, the AChR open-channel probability was markedly affected both by the extent of receptor phosphorylation in different subunits and by agonist concentration. Notably, the spontaneous open-channel probability of serine-phosphorylated AChRs is significantly higher than that of AChRs phosphorylated on tyrosine residues or of unphosphorylated AChRs. Channel activation by protein kinase A and protein kinase C is correlated with AChR phosphorylation and is abolished by alpha-bungarotoxin.... Protein phosphorylation/ion channels, RA1


Descriptors :   *IONS , *PROTEINS , *CHANNELS , *PHOSPHORYLATION , FREQUENCY , CONTRAST , ACTIVATION , PROBABILITY , PROTOTYPES , DEOXYRIBONUCLEIC ACIDS , GAMMA RAYS , PHOSPHATASES , CHEMORECEPTORS , ACETYLCHOLINE , SERINE , TYROSINE , RESIDUES , CURRENTS , SYNAPSE , PHYSIOLOGY , NICOTINE , PHOSPHORUS TRANSFERASES , LIGANDS , SENSITIVITY , SODIUM , COVALENT BONDS , CONDUCTIVITY , MODIFICATION , LIPIDS


Subject Categories : Anatomy and Physiology
      Medicine and Medical Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE