Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2005-7-19
pubmed:abstractText
The hydroxamic acid (HAA) analogue pan-histone deacetylase (HDAC) inhibitors (HDIs) LAQ824 and LBH589 have been shown to induce acetylation and inhibit the ATP binding and chaperone function of heat shock protein (HSP) 90. This promotes the polyubiquitylation and degradation of the pro-growth and pro-survival client proteins Bcr-Abl, mutant FLT-3, c-Raf, and AKT in human leukemia cells. HDAC6 is a member of the class IIB HDACs. It is predominantly cytosolic, microtubule-associated alpha-tubulin deacetylase that is also known to promote aggresome inclusion of the misfolded polyubiquitylated proteins. Here we demonstrate that in the Bcr-abl oncogene expressing human leukemia K562 cells, HDAC6 can be co-immunoprecipitated with HSP90, and the knock-down of HDAC6 by its siRNA induced the acetylation of HSP90 and alpha-tubulin. Depletion of HDAC6 levels also inhibited the binding of HSP90 to ATP, reduced the chaperone association of HSP90 with its client proteins, e.g. Bcr-Abl, and induced polyubiquitylation and partial depletion of Bcr-Abl. Conversely, the ectopic overexpression of HDAC6 inhibited LAQ824-induced acetylation of HSP90 and alpha-tubulin and reduced LAQ824-mediated depletion of Bcr-Abl, AKT, and c-Raf. Collectively, these findings indicate that HDAC6 is also an HSP90 deacetylase. Targeted inhibition of HDAC6 leads to acetylation of HSP90 and disruption of its chaperone function, resulting in polyubiquitylation and depletion of pro-growth and pro-survival HSP90 client proteins including Bcr-Abl. Depletion of HDAC6 sensitized human leukemia cells to HAA-HDIs and proteasome inhibitors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/HDAC6 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/HSP90 Heat-Shock Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Histone Deacetylase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Histone Deacetylases, http://linkedlifedata.com/resource/pubmed/chemical/Hydroxamic Acids, http://linkedlifedata.com/resource/pubmed/chemical/LAQ824, http://linkedlifedata.com/resource/pubmed/chemical/LBH589, http://linkedlifedata.com/resource/pubmed/chemical/Molecular Chaperones, http://linkedlifedata.com/resource/pubmed/chemical/Neoplasm Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitin
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26729-34
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Inhibition of histone deacetylase 6 acetylates and disrupts the chaperone function of heat shock protein 90: a novel basis for antileukemia activity of histone deacetylase inhibitors.
pubmed:affiliation
Department of Interdisciplinary Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida 33612, USA.
pubmed:publicationType
Journal Article