Site-specific phosphorylation of neurofilament-L is mediated by calcium/calmodulin-dependent protein kinase II in the apical dendrites during long-term potentiation.
Neurofilament-L (NF-L), one subunit of the neuronal intermediate filaments, is a major element of neuronal cytoskeletons. The dynamics of NF-L are regulated by phosphorylation of its head domain. The phosphorylation sites of the NF-L head domain by protein kinase A, protein kinase C, and Rho-associated kinase have been previously identified, and those by calcium/calmodulin-dependent protein kinase II (CaMKII) were identified in this study. A series of site- and phosphorylation state-specific antibodies against NF-L was prepared to investigate NF-L phosphorylation in neuronal systems. Long-term potentiation (LTP) is a cellular model of neuronal plasticity that is thought to involve the phosphorylation of various proteins. NF-L is considered a possible substrate for phosphorylation. During LTP stimulation of mouse hippocampal slices, the series of antibodies demonstrated the increase in the phosphorylation level of Ser(57) in NF-L and the visualization of the localized distribution of Ser(57) phosphorylation in a subpopulation of apical dendrites of the pyramidal neurons. Furthermore, Ser(57) phosphorylation during LTP is suggested to be mediated by CaMKII. Here we show that NF-L is phosphorylated by CaMKII in a subpopulation of apical dendrites during LTP, indicating that Ser(57) is a novel phosphorylation site of NF-L in vivo related to the neuronal signal transduction.
Hashimoto
R
R
Department of Clinical Neuroscience, Graduate School of Medicine, Institute for Protein Research, Osaka University, Osaka, Japan.
Nakamura
Y
Y
Komai
S
S
Kashiwagi
Y
Y
Tamura
K
K
Goto
T
T
Aimoto
S
S
Kaibuchi
K
K
Shiosaka
S
S
Takeda
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D000001:Calcimycin / Q000494:pharmacology; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002417:Cattle; D003712:Dendrites / Q000201:enzymology*; D007476:Ionophores / Q000494:pharmacology; D017774:Long-Term Potentiation; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D016900:Neurofilament Proteins / Q000737:chemistry / Q000378:metabolism*; D009473:Neuronal Plasticity; D009474:Neurons / Q000648:ultrastructure*; D010766:Phosphorylation; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D017385:Sequence Homology
D007476:Ionophores; D016900:Neurofilament Proteins; D011994:Recombinant Proteins; C044882:neurofilament protein L; D000001:Calcimycin; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases