CaM kinase II selectively signals to histone deacetylase 4 during cardiomyocyte hypertrophy
J. Clin. Invest. Johannes Backs, et al. 116:1853 doi:10.1172/JCI27438 [Go to this article.]

Figure 4
Mapping the CaMKII-responsive region of HDAC4. (A) Chimeric HDAC4/5 proteins (as indicated) were expressed in COS cells in the presence of CaMKIIδB-T287D. Subcellular localization was verified by immunocytochemistry. Amino acids 529–657 were revealed to be required for cytosolic accumulation of HDAC4 in response to CaMKIIδB-T287D. (B) An HDAC5 mutant, in which the CaMKII consensus sites were mutated to the corresponding sites in HDAC4, was expressed in COS cells alone or with CaMKI c.a. and CaMKIIδB-T287D. This mutant was responsive to CaMKI but not to CaMKIIδB-T287D. Magnification, ×40. (C–F) Coimmunoprecipitation assays with COS cell lysates. (C) COS cells were cotransfected with FLAG-pcDNA, -HDAC4, or -HDAC5 and Myc-CaMKIIδB-T287D. Various stringency conditions of the immunoprecipitation buffer were tested as indicated. Only HDAC4 binds strongly to CaMKII. (D) Cotransfection of FLAG-HDAC4 with either WT or constitutively activated Myc–CaMKIIδB-T287D. Only the activated form of CaMKIIδB physically interacted with HDAC4. (E) IP of FLAG-HDAC4 deletion mutants coexpressed with Myc-CaMKIIδB-T287D to identify a domain of HDAC4 that binds to activated CaMKIIδB. (F) Based on the coimmunoprecipitation data, amino acids 585–608 of HDAC4 were identified to be required for physical interaction with CaMKIIδB-T287D and, therefore, define a CaMKII docking site.