ERK1/2, p38, and JNK regulate the expression and the activity of the three isoforms of the Na+ /Ca2+ exchanger, NCX1, NCX2, and NCX3, in neuronal PC12 cells.
We evaluated whether changes in expression and activity of the three sodium/calcium exchanger isoforms, NCX1, NCX2, and NCX3 occurred in PC12 cells when the extracellular-signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK), and p38 mitogen-activated protein kinases (MAPKs) were silenced, pharmacologically blocked, or activated with nerve growth factor (NGF). Several findings suggesting that MAPKs control NCX emerged: (1) A decrease in NCX1 and NCX3 basal expression occurred when JNK or MEK1, the extracellular-signal-regulated kinases 1/2 upstream activator, were pharmacologically blocked, respectively; (2) NGF increased cAMP response element-binding 1 (CREB1) and Specificity Protein 1 (Sp1) binding to ncx1 promoter and CREB1 binding to two different sequences close to ncx2 transcription start site on genomic DNA; (3) An up-regulation of NCX1 and NCX3, abrogated upon either MEK1 or p38 blockade, and a down-regulation of NCX2, abolished upon p38 blockade, occurred upon NGF-induced MAPK activation. The NCX1 up-regulation was abolished upon either CREB1 or Sp1 silencing, whereas NCX2 down-regulation was abrogated only by CREB1 silencing. The NCX3 up-regulation was unaffected by CREB1 or Sp1 silencing and abolished upon proteasomal inhibition; (4) Whole-cell Na(+) /Ca(2+) exchange decreased when MEK1 and JNK were blocked and increased when MAPKs were activated by NGF. Collectively, these results demonstrate a MAPK-dependent regulation of NCX expression and activity which could be relevant in mediating some of the effects of MAPKs in neurons.
Fondazione IRCCS SDN, Naples, Italy.
Rossana
R
Sirabella
Agnese
A
Secondo
Anna
A
Pannaccione
Pasquale
P
Molinaro
Luigi
L
Formisano
Natascia
N
Guida
Gianfranco
G
Di Renzo
Lucio
L
Annunziato
Mauro
M
Cataldi
D000818:Animals; D050882:CREB-Binding Protein / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D047369:Chromatin Immunoprecipitation; D000242:Cyclic AMP / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D048670:MAP Kinase Kinase 4; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D016716:PC12 Cells / Q000187:drug effects; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D019831:Sodium-Calcium Exchanger / Q000145:classification / Q000378:metabolism*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D034741:RNA, Small Interfering; C110927:Slc8a2 protein, rat; C491102:Slc8a3 protein, rat; D019831:Sodium-Calcium Exchanger; D016329:Sp1 Transcription Factor; C110374:sodium-calcium exchanger 1; D020932:Nerve Growth Factor; D000242:Cyclic AMP; D050882:CREB-Binding Protein; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D002118:Calcium