Human class I histone deacetylase complexes show enhanced catalytic activity in the presence of ATP and co-immunoprecipitate with the ATP-dependent chaperone protein Hsp70
Human class I histone deacetylase complexes show enhanced catalytic activity in the presence of ATP and co-immunoprecipitate with the ATP-dependent chaperone protein Hsp70
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DOI：
10.1074/jbc.m107942200
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发表时间：
2002-03-15
影响因子：
4.8
通讯作者：
Turner, BM
中科院分区：
文献类型：
--
作者：
Johnson, CA;White, DA;Turner, BM
抗组蛋白脱乙酰酶(HDAC)抗体已被用于免疫分离HeLa细胞提取物中的脱乙酰酶复合体。含有HDACI、HDAC3、HDAC6和HDAC1+2作为催化亚基的络合物已被用于基于抗体的分析，该分析检测特定赖氨酸的整个病程的脱乙酰基。11类脱乙酰酶HDAC6在本实验中没有活性，但三种I类酶对所有被测试的组蛋白赖氨酸进行脱乙酰化，尽管效率不同。与HDAC1相比，HDAC3优先脱乙酰化H4的赖氨酸5和12以及H2 A的赖氨酸5。纯化的单核小体中的H4尾巴对HDAC1和HDAC3的脱乙酰基都不敏感，除非在反应混合物中加入ATP。令人惊讶的是，ATP如此始终如一地促进了两种酶复合体对游离的非核小体组蛋白的切割，但不是小肽.我们没有发现证据表明ATP是通过HDAC复合体成分的磷酸化来发挥作用的，但我们已经证明HDAC 1、2和3都与依赖于ATP的伴侣蛋白Hsp70共沉淀。另一种常见的ATP依赖伴侣Hsp90在所有测试的HDAC复合体中都不存在，而Hsp60仅与HDAC1相关。我们认为HSP伴侣蛋白通过依赖于ATP对蛋白质底物的操纵来增强HDAC复合体的脱乙酰酶活性。
Antibodies to histone deacetylases (HDACs) have been used to immuno-isolate deacetylase complexes from HeLa cell extracts. Complexes shown to contain HDAC I, HDAC3, HDAC6, and HDAC1+2 as their catalytic subunits have been used in an antibody-based assay that detects deacetylation of whole histories at defined lysines. The class 11 deacetylase HDAC6 was inactive in this assay, but the three class I enzymes deacetylated all histone lysines tested, although with varying efficiency. In comparison to HDAC1, HDAC3 preferentially deacetylated lysines 5 and 12 of H4 and lysine 5 of H2A. H4 tails in purified mononucleosomes were refractory to deacetylation by both HDAC1 and HDAC3, unless ATP was added to the reaction mix. Surprisingly, ATP a so consistently enhanced cleavage of free, non-nucleosomal histones, but not small peptides, by both enzyme complexes. We found no evidence that ATP operates by phosphorylation of components of the HDAC complex but have shown that HDACs 1, 2, and 3 all co-immunoprecipitate with the ATP-dependent chaperone protein Hsp70. Another common ATP-dependent chaperone, Hsp90, was absent from all HDAC complexes tested, whereas Hsp60 associated with HDAC1 only. We suggest that Hsp chaperone proteins enhance the deacetylase activity of HDAC complexes by ATP-dependent manipulation of protein substrates.