title: A calcium- and calmodulin-dependent kinase Ialpha/microtubule affinity regulating kinase 2 signaling cascade mediates calcium-dependent neurite outgrowth.
abstract: Calcium is a critical regulator of neuronal differentiation and neurite outgrowth during development, as well as synaptic plasticity in adulthood. Calcium- and calmodulin-dependent kinase I (CaMKI) can regulate neurite outgrowth; however, the signal transduction cascades that lead to its physiological effects have not yet been elucidated. CaMKIalpha was therefore used as bait in a yeast two-hybrid assay and microtubule affinity regulating kinase 2 (MARK2)/Par-1b was identified as an interacting partner of CaMKI in three independent screens. The interaction between CaMKI and MARK2 was confirmed in vitro and in vivo by coimmunoprecipitation. CaMKI binds MARK2 within its kinase domain, but only if it is activated by calcium and calmodulin. Expression of CaMKI and MARK2 in Neuro-2A (N2a) cells and in primary hippocampal neurons promotes neurite outgrowth, an effect dependent on the catalytic activities of these enzymes. In addition, decreasing MARK2 activity blocks the ability of the calcium ionophore ionomycin to promote neurite outgrowth. Finally, CaMKI phosphorylates MARK2 on novel sites within its kinase domain. Mutation of these phosphorylation sites decreases both MARK2 kinase activity and its ability to promote neurite outgrowth. Interaction of MARK2 with CaMKI results in a novel, calcium-dependent pathway that plays an important role in neuronal differentiation.
authors: Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06508, USA.
authors: Nataliya V
authors: NV
authors: Uboha
authors: Marc
authors: M
authors: Flajolet
authors: Angus C
authors: AC
authors: Nairn
authors: Marina R
authors: MR
authors: Picciotto
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology; D051379:Mice; D048052:Mitogen-Activated Protein Kinase 3; D016501:Neurites / Q000502:physiology*; D009447:Neuroblastoma / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats
chemical_list: C094670:MARK2 protein, human; D017346:Protein Serine-Threonine Kinases; C517596:CAMK1 protein, human; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517598:Camk1 protein, mouse; C517599:Camk1 protein, rat; C517681:Pnck protein, mouse; C517682:Pnck protein, rat; D048052:Mitogen-Activated Protein Kinase 3; D002118:Calcium