Linked Life Data

17234752

Source:http://linkedlifedata.com/resource/pubmed/id/17234752

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-1-19
pubmed:abstractText
The prostate-specific homeodomain protein NKX3.1 is a tumor suppressor that is commonly down-regulated in human prostate cancer. Using an NKX3.1 affinity column, we isolated topoisomerase I (Topo I) from a PC-3 prostate cancer cell extract. Topo I is a class 1B DNA-resolving enzyme that is ubiquitously expressed in higher organisms and many prokaryotes. NKX3.1 interacts with Topo I to enhance formation of the Topo I-DNA complex and to increase Topo I cleavage of DNA. The two proteins interacted in affinity pull-down experiments in the presence of either DNase or RNase. The NKX3.1 homeodomain was essential, but not sufficient, for the interaction with Topo I. NKX3.1 binding to Topo I occurred independently of the Topo I NH2-terminal domain. The binding of equimolar amounts of Topo I to NKX3.1 caused displacement of NKX3.1 from its cognate DNA recognition sequence. Topo I activity in prostates of Nkx3.1+/- and Nkx3.1-/- mice was reduced compared with wild-type mice, whereas Topo I activity in livers, where no NKX3.1 is expressed, was independent of Nkx3.1 genotype. Endogenous Topo I and NKX3.1 could be coimmunoprecipitated from LNCaP cells, where NKX3.1 and Topo I were found to colocalize in the nucleus and comigrate within the nucleus in response to either gamma-irradiation or mitomycin C exposure, two DNA-damaging agents. This is the first report that a homeodomain protein can modify the activity of Topo I and may have implications for organ-specific DNA replication, transcription, or DNA repair.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
455-64
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
NKX3.1 homeodomain protein binds to topoisomerase I and enhances its activity.
pubmed:affiliation
Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20007-2197, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural