signalling from glurs is mediated by the presence of an abundance of proteins, especially kinases, that are localized to the postsynaptic density. these include calcium-dependent calmodulin, camkii (calmodulin-dependent protein kinase ii), pkc (protein kinase c), pka (protein kinase a), protein phosphatase-1 (pp-1), and fyn tyrosine kinase. certain signallers, such as camkii, are upregulated in response to activity.