NMDA receptor subunit composition controls dendritogenesis of hippocampal neurons through CAMKII, CREB-P, and H3K27ac.
Dendrite arbor growth, or dendritogenesis, is choreographed by a diverse set of cues, including the NMDA receptor (NMDAR) subunits NR2A and NR2B. While NR1NR2B receptors are predominantly expressed in immature neurons and promote plasticity, NR1NR2A receptors are mainly expressed in mature neurons and induce circuit stability. How the different subunits regulate these processes is unclear, but this is likely related to the presence of their distinct C-terminal sequences that couple different signaling proteins. Calcium-calmodulin-dependent protein kinase II (CaMKII) is an interesting candidate as this protein can be activated by calcium influx through NMDARs. CaMKII triggers a series of biochemical signaling cascades, involving the phosphorylation of diverse targets. Among them, the activation of cAMP response element-binding protein (CREB-P) pathway triggers a plasticity-specific transcriptional program through unknown epigenetic mechanisms. Here, we found that dendritogenesis in hippocampal neurons is impaired by several well-characterized constructs (i.e., NR2B-RS/QD) and peptides (i.e., tatCN21) that specifically interfere with the recruitment and interaction of CaMKII with the NR2B C-terminal domain. Interestingly, we found that transduction of NR2AΔIN, a mutant NR2A construct with increased interaction to CaMKII, reactivates dendritogenesis in mature hippocampal neurons in vitro and in vivo. To gain insights into the signaling and epigenetic mechanisms underlying NMDAR-mediated dendritogenesis, we used immunofluorescence staining to detect CREB-P and acetylated lysine 27 of histone H3 (H3K27ac), an activation-associated histone tail mark. In contrast to control mature neurons, our data shows that activation of the NMDAR/CaMKII/ERK-P/CREB-P signaling axis in neurons expressing NR2AΔIN is not correlated with increased nuclear H3K27ac levels.
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.|FONDAP Center for Genome Regulation, Santiago, Chile.
Fernando J
FJ
Bustos
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Nur
N
Jury
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Pablo
P
Martinez
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Estibaliz
E
Ampuero
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Matias
M
Campos
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Sebastian
S
Abarzúa
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.|FONDAP Center for Genome Regulation, Santiago, Chile.
Karen
K
Jaramillo
Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, University of Heidelberg, German Red Cross Blood Service Baden-Württemberg-Hessen, Mannheim, Germany.
Susanne
S
Ibing
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Muriel D
MD
Mardones
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.
Henny
H
Haensgen
Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, University of Heidelberg, German Red Cross Blood Service Baden-Württemberg-Hessen, Mannheim, Germany.
Julia
J
Kzhyshkowska
Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile.
Maria Florencia
MF
Tevy
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.
Rachael
R
Neve
Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile.
Magdalena
M
Sanhueza
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Lorena
L
Varela-Nallar
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.|FONDAP Center for Genome Regulation, Santiago, Chile.
Martín
M
Montecino
Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile.
Brigitte
B
van Zundert
D000107:Acetylation; D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D003712:Dendrites / Q000187:drug effects / Q000201:enzymology*; D005865:Gestational Age; D006624:Hippocampus / Q000187:drug effects / Q000196:embryology / Q000201:enzymology*; D006657:Histones / Q000378:metabolism*; D009154:Mutation; D055495:Neurogenesis / Q000187:drug effects; D009473:Neuronal Plasticity / Q000187:drug effects; D010455:Peptides / Q000494:pharmacology; D010641:Phenotype; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D034622:RNA Interference; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection
D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017362:Cyclic AMP Response Element-Binding Protein; D006657:Histones; D010455:Peptides; D047428:Protein Kinase Inhibitors; D016194:Receptors, N-Methyl-D-Aspartate; C508137:Creb1 protein, rat; C121001:NR2B NMDA receptor; C000616211:tatCN21 peptide
CaMKII; H3K27Ac; NMDAR; brain; cultures; dendrites; histone modification; neuron; spines