Translation Regulation of Arc
Arc protein is present at low levels in cultured hippocampal neurons.
Transfection of Arc cDNA fails to result in high expression of Arc protein.
Q: Is expression of Arc inhibited at the translational level?
forskolin enhances Arc expression
Arc-EYFP protein levels are increased by 4 hours of forskolin, an activator of the cAMP pathway
(as indicated by the 10-fold reduction in exposure time after forskolin). Note that Arc protein is mainly localized to the nucleus.
Bottom panel: over-exposure (8 sec) reveals a small fraction of Arc in the dendrites; Arc is enriched in spines.
NMDA receptors regulate Arc expression
Regulation of Arc expression does not depend on the untranslated regions of the Arc mRNA:
5'- and 3'UTR are not required for regulation of Arc expression
MNDA DA interactions
(isoproterenol = β-adrenergic agonist; SKF = dopamine D1 agonist; MK801 = NMDA receptor antagonist)
Working model for NMDA receptor regulation of Arc expression: Adenylyl cyclase 1 is conicidence detector
Emotion plus LTP equals memory consolidation