Modulation of Histone Deacetylase 6 (HDAC6) Nuclear Import and Tubulin Deacetylase Activity through Acetylation

• Published in: The Journal of biological chemistry 2012-08, Vol.287 (34), p.29168-29174
• Main Authors: Liu, Yuanjing, Peng, Lirong, Seto, Edward, Huang, Suming, Qiu, Yi
• Format: Article
• Language: English
• Subjects: Acetylation; Active Transport, Cell Nucleus - physiology; alpha Karyopherins - genetics; alpha Karyopherins - metabolism; Animals; Cell Biology; Cell Motility; Cell Nucleus - genetics; Cell Nucleus - metabolism; Chromatin Histone Modification; HeLa Cells; Histone Deacetylase; Histone Deacetylase 6; Histone Deacetylases - genetics; Histone Deacetylases - metabolism; Humans; Mice; Mutation; Nuclear Import; Nuclear Localization Signals - genetics; Nuclear Localization Signals - metabolism; p300-CBP Transcription Factors - genetics; p300-CBP Transcription Factors - metabolism; Protein Processing, Post-Translational - physiology; Transcription Coactivators; Tubulin; Tubulin - genetics; Tubulin - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M112.371120

The reversible acetylation of histones and non-histone proteins by histone acetyltransferases and deacetylases (HDACs) plays a critical role in many cellular processes in eukaryotic cells. HDAC6 is a unique histone deacetylase with two deacetylase domains and a C-terminal zinc finger domain. HDAC6 resides mainly in the cytoplasm and regulates many important biological processes, including cell migration and degradation of misfold proteins. HDAC6 has also been shown to localize in the nucleus to regulate transcription. However, how HDAC6 shuttles between the nucleus and cytoplasm is largely unknown. In addition, it is not clear how HDAC6 enzymatic activity is modulated. Here, we show that HDAC6 can be acetylated by p300 on five clusters of lysine residues. One cluster (site B) of acetylated lysine is in the N-terminal nuclear localization signal region. These lysine residues in site B were converted to glutamine to mimic acetylated lysines. The mutations significantly reduced HDAC6 tubulin deacetylase activity and further impaired cell motility, but had no effect on histone deacetylase activity. More interestingly, these mutations retained HDAC6 in the cytoplasm by blocking the interaction with the nuclear import protein importin-α. The retention of HDAC6 in the cytoplasm by acetylation eventually affects histone deacetylation. Thus, we conclude that acetylation is an important post-translational modification that regulates HDAC6 tubulin deacetylase activity and nuclear import. Background: HDAC6 is an important deacetylase for cytoplasmic and nuclear function. However, how it is regulated is unknown. Results: HDAC6 acetylation sites were determined, and acetylation affected HDAC6 enzymatic activity and nuclear transport. Conclusion: Acetylation is an important post-translational modification that regulates HDAC6 function. Significance: This study provides insight into regulation of HDAC6 function.