ERK2-type mitogen-activated protein kinase (MAPK) and its substrates in postsynaptic density fractions from the rat brain.
Mitogen-activated protein kinase (MAPK) and MAPK kinase (MAPKK) were detected by Western blotting in the synaptic fraction prepared from the rat brain. There were two bands immunoreactive to the anti-MAPK antiserum in the soluble, P2, synaptosome, and synaptic plasma membrane fractions. These immunoreactive bands possibly corresponded to extracellular signal-regulated kinase (ERK) 1 and 2 (Boulton et al., 1991b), respectively. Only ERK2 was detected in the postsynaptic density (PSD) fraction. We then surveyed MAPK substrates in the synaptic fractions using purified Xenopus MAPK (ERK2-type MAPK), and found a number of MAPK substrates unique to the PSD fraction. Thus, ERK2 is present in the synapse, especially at the postsynaptic site, and it may play a role(s) in synaptic function via the phosphorylation of synapse-specific substrates. Developmental changes in ERK2 also supported its role in the synapse.
D000367:Age Factors; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D007150:Immunohistochemistry; D008934:Mitogens / Q000276:immunology*; D010766:Phosphorylation; D017729:Presynaptic Terminals / Q000378:metabolism*; D011494:Protein Kinases / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar
D008934:Mitogens; D011494:Protein Kinases