CaM kinase II selectively signals to histone deacetylase 4 during cardiomyocyte hypertrophy
Johannes Backs, Kunhua Song, Svetlana Bezprozvannaya, Shurong Chang, Eric N. Olson
Johannes Backs, Kunhua Song, Svetlana Bezprozvannaya, Shurong Chang, Eric N. Olson
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Research Article Cardiology

CaM kinase II selectively signals to histone deacetylase 4 during cardiomyocyte hypertrophy

Abstract

Class IIa histone deacetylases (HDACs) regulate a variety of cellular processes, including cardiac growth, bone development, and specification of skeletal muscle fiber type. Multiple serine/threonine kinases control the subcellular localization of these HDACs by phosphorylation of common serine residues, but whether certain class IIa HDACs respond selectively to specific kinases has not been determined. Here we show that calcium/calmodulin-dependent kinase II (CaMKII) signals specifically to HDAC4 by binding to a unique docking site that is absent in other class IIa HDACs. Phosphorylation of HDAC4 by CaMKII promotes nuclear export and prevents nuclear import of HDAC4, with consequent derepression of HDAC target genes. In cardiomyocytes, CaMKII phosphorylation of HDAC4 results in hypertrophic growth, which can be blocked by a signal-resistant HDAC4 mutant. These findings reveal a central role for HDAC4 in CaMKII signaling pathways and have implications for the control of gene expression by calcium signaling in a variety of cell types.

Authors

Johannes Backs, Kunhua Song, Svetlana Bezprozvannaya, Shurong Chang, Eric N. Olson

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Figure 6

Cytosolic accumulation of HDAC4 in cardiomyocytes.

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Cytosolic accumulation of HDAC4 in cardiomyocytes. (A–C) NRVMs were infe...
(A–C) NRVMs were infected with adenoviral FLAG-HDAC4 or GFP-HDAC5. Subcellular distribution of HDAC4 and HDAC5 was verified following stimulation with PE (20 μM) for 4 hours. NRVMs were pretreated with the kinase inhibitors staurosporine (Stauro; 500 nM), KN93 (5 μM), KN62 (10 μM), AIPII-2 (500 nM), Bis (2.5 μM), Gö6976 (200 nM), or H89 (1 μM). (A) Representative images. (B) Quantitative analysis of time-dependent PE-induced cytosolic accumulation of HDAC4. (C) Effects of kinase inhibitors on PE-induced cytosolic accumulation of HDAC4. (D) NRVMs were treated with PMA with and without Bis. Immunoblotting was performed with antibodies against PKD (lower panel) and phospho-S744/S748 PKD (p-PKD; upper panel). (E–G) NRVMs were infected with adenoviruses encoding FLAG-HDAC4-WT or FLAG-HDAC4-S246,467,632A (FLAG-HDAC4-S/A). One day after infection, cells were grown in serum-free media for 24 hours and then stimulated with PE (20 μM). Cells were fixed and stained with anti-sarcomeric α-actinin (red signal; 24 hours after PE) (E) or anti-ANP (perinuclear green signal; 12 hours after PE) (G). HDAC4-infected NRVMs were identified by anti-FLAG staining (green in E or red in G). (F) [3H]-leucine was added to NRVMs 2 hours after PE stimulation and [3H]-leucine incorporation was measured 24 hours later. *P < 0.05 vs. WT without PE and vs. S/A with PE. NS, not significant vs. S/A without PE. (A, E, and G) Representative images were captured at a magnification of ×40.