title: Negative regulation of histone deacetylase 8 activity by cyclic AMP-dependent protein kinase A.
abstract: Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from lysine residues of histone and nonhistone proteins. Recent studies suggest that they are key regulators of many cellular events, including cell proliferation and cancer development. Human class I HDACs possess homology to the yeast RPD3 protein and include HDAC1, HDAC2, HDAC3, and HDAC8. While HDAC1, HDAC2, and HDAC3 have been characterized extensively, almost nothing is known about HDAC8. Here we report that HDAC8 is phosphorylated by cyclic AMP-dependent protein kinase A (PKA) in vitro and in vivo. The PKA phosphoacceptor site of HDAC8 is Ser(39), a nonconserved residue among class I HDACs. Mutation of Ser(39) to Ala enhances the deacetylase activity of HDAC8. In contrast, mutation of Ser(39) to Glu or induction of HDAC8 phosphorylation by forskolin, a potent activator of adenyl cyclase, decreases HDAC8's enzymatic activity. Remarkably, inhibition of HDAC8 activity by hyperphosphorylation leads to hyperacetylation of histones H3 and H4, suggesting that PKA-mediated phosphorylation of HDAC8 plays a central role in the overall acetylation status of histones.
authors.affiliation: H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL 33612, USA.
authors.forename: Heehyoung
authors.initials: H
authors.lastname: Lee
authors.forename: Natalie
authors.initials: N
authors.lastname: Rezai-Zadeh
authors.forename: Edward
authors.initials: E
authors.lastname: Seto
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D020134:Catalytic Domain / Q000235:genetics; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D006367:HeLa Cells; D006655:Histone Deacetylases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000737:chemistry
chemical_list: D018076:DNA, Complementary; D006657:Histones; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D012694:Serine; D017868:Cyclic AMP-Dependent Protein Kinases; C409470:HDAC8 protein, human; D006655:Histone Deacetylases