title: Potentiation of ATP-induced currents due to the activation of P2X receptors by ubiquitin carboxy-terminal hydrolase L1.
abstract: Mammalian neuronal cells abundantly express a de-ubiquitinating isozyme, ubiquitin carboxy-terminal hydrolase L1 (UCH L1). Loss of UCH L1 function causes dying-back type of axonal degeneration. However, the function of UCH L1 in neuronal cells remains elusive. Here we show that overexpression of UCH L1 potentiated ATP-induced currents due to the activation of P2X receptors that are widely distributed in the brain and involved in various biological activities including neurosecretion. ATP-induced inward currents were measured in mock-, wild-type or mutant (C90S)-UCH L1-transfected PC12 cells under the conventional whole-cell patch clamp configuration. The amplitude of ATP-induced currents was significantly greater in both wild-type and C90S UCH L1-transfected cells, suggesting that hydrolase activity was not involved but increased level of mono-ubiquitin might play an important role. The increased currents were dependent on cAMP-dependent protein kinase (PKA) and Ca2+ and calmodulin-dependent protein kinase (CaMKII) but not protein kinase C. In addition, ATP-induced currents were likely to be modified via dopamine and cyclic AMP-regulated phosphoprotein (DARPP-32) that is regulated by PKA and phosphatases. Our finding shows the first evidence that there is a relationship between UCH L1 and neurotransmitter receptor, suggesting that UCH L1 may play an important role in synaptic activity.
authors.affiliation: Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Manago
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kanahori
authors.forename: Aki
authors.initials: A
authors.lastname: Shimada
authors.forename: Ayumi
authors.initials: A
authors.lastname: Sato
authors.forename: Taiju
authors.initials: T
authors.lastname: Amano
authors.forename: Yae
authors.initials: Y
authors.lastname: Sato-Sano
authors.forename: Rieko
authors.initials: R
authors.lastname: Setsuie
authors.forename: Mikako
authors.initials: M
authors.lastname: Sakurai
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Aoki
authors.forename: Yu-Lai
authors.initials: YL
authors.lastname: Wang
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Osaka
authors.forename: Keiji
authors.initials: K
authors.lastname: Wada
authors.forename: Mami
authors.initials: M
authors.lastname: Noda
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004298:Dopamine / Q000494:pharmacology; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D008564:Membrane Potentials / Q000187:drug effects* / Q000502:physiology; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D016716:PC12 Cells; D018408:Patch-Clamp Techniques / Q000379:methods; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D058469:Receptors, Purinergic P2X; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014162:Transfection / Q000379:methods; D025801:Ubiquitin / Q000378:metabolism; D043222:Ubiquitin Thiolesterase / Q000378:metabolism*
chemical_list: D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D004791:Enzyme Inhibitors; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X; D025801:Ubiquitin; D049452:Green Fluorescent Proteins; D000255:Adenosine Triphosphate; D017868:Cyclic AMP-Dependent Protein Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C489034:UCHL1 protein, rat; D043222:Ubiquitin Thiolesterase; D002118:Calcium; D004298:Dopamine