Skip to main content
. Author manuscript; available in PMC: 2015 Feb 13.
Published in final edited form as: Annu Rev Neurosci. 2012 Apr 5;35:417–443. doi: 10.1146/annurev-neuro-060909-153138

Figure 6.

Figure 6

Schema for coupling mGluR5 to FMRP-regulated protein synthesis. Several lines of evidence suggest that mGluR5 couples to FMRP-regulated protein synthesis through multiple pathways. (a) Activation of mGluR5 directly stimulates mRNA translation through the ERK signaling pathway. (b) Additionally, activation of mGluR5 can trigger dephosphorylation of FMRP by PP2A, which derepresses translation. (c) FMRP is rapidly synthesized in response to mGluR5 activation, providing a negative-feedback loop to turn off protein synthesis. (d) Several FMRP target proteins are known components of mGluR5 signaling pathways, suggesting that positive feedback may occur, particularly in the context of FX. Abbreviations: ERK, extracellular signal–regulated kinase; FMRP, fragile X mental retardation protein; FX, fragile X; mGluR, metabotropic glutamate receptor; PP2A, protein phosphatase 2A.