title: Intracellular trafficking of histone deacetylase 4 regulates neuronal cell death.
abstract: Histone deacetylase 4 (HDAC4) undergoes signal-dependent shuttling between the cytoplasm and nucleus, which is regulated in part by calcium/calmodulin-dependent kinase (CaMK)-mediated phosphorylation. Here, we report that HDAC4 intracellular trafficking is important in regulating neuronal cell death. HDAC4 is normally localized to the cytoplasm in brain tissue and cultured cerebellar granule neurons (CGNs). However, in response to low-potassium or excitotoxic glutamate conditions that induce neuronal cell death, HDAC4 rapidly translocates into the nucleus of cultured CGNs. Treatment with the neuronal survival factor BDNF suppresses HDAC4 nuclear translocation, whereas a proapoptotic CaMK inhibitor stimulates HDAC4 nuclear accumulation. Moreover, ectopic expression of nuclear-localized HDAC4 promotes neuronal apoptosis and represses the transcriptional activities of myocyte enhancer factor 2 and cAMP response element-binding protein, survival factors in neurons. In contrast, inactivation of HDAC4 by small interfering RNA or HDAC inhibitors suppresses neuronal cell death. Finally, an increase of nuclear HDAC4 in granule neurons is also observed in weaver mice, which harbor a mutation that promotes CGN apoptosis. Our data identify HDAC4 and its intracellular trafficking as key effectors of multiple pathways that regulate neuronal cell death.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina 27710, USA.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Bolger
authors.forename: Tso-Pang
authors.initials: TP
authors.lastname: Yao
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000096:biosynthesis* / Q000235:genetics; D007424:Intracellular Fluid / Q000187:drug effects / Q000201:enzymology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology
chemical_list: D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; C498618:Hdac5 protein, mouse; D006655:Histone Deacetylases