Figure 12.
Proposed model of physiological function of Homer3 phosphorylation in Purkinje cells. Homer3 phosphorylation by CaMKII occurs within 2 min in response to synaptic activity, which regulates Homer3-mediated molecular coupling such as mGluR1α–IP3R1 in Purkinje cells spine, designated as “early-phase uncoupling,” contrasting with Homer1a-mediated uncoupling, which requires de novo gene expression and takes 1–4 h, “late-phase uncoupling.” Additionally, when Homer3 is phosphorylated by CaMKII at the spine, Homer3 translocates from spine to dendrites, which can function as a signal transmitter from activated synapse. ER, Endoplasmic reticulum.