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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2006-5-22
pubmed:abstractText
Mammalian DNA polymerase delta (pol delta), a key enzyme of chromosomal DNA replication, consists of four subunits as follows: the catalytic subunit; p125, which is tightly associated with the p50 subunit; p68, a proliferating cell nuclear antigen (PCNA)-binding protein; and a fourth subunit, p12. In this study, the functional roles of the p12 subunit of pol delta were studied. The inter-subunit interactions of the p12 subunit were determined by yeast two-hybrid assays and by pulldown assays. These assays revealed that p12 interacts with p125 as well as p50. This dual interaction of p12 suggests that it may serve to stabilize the p125-p50 interaction. p12 was shown to be a novel PCNA-binding protein. This was confirmed by identification of a PCNA-binding motif at its N terminus by binding assays and by site-directed mutagenesis. The activities and reaction products of recombinant pol delta containing a p12 mutant defective in PCNA binding, as well as purified recombinant pol delta and its subassemblies, were analyzed. Our results indicate that p12 contributes to PCNA-dependent pol delta activity, i.e. the p12-PCNA interaction is functional. Our data indicate that both p12 and p68 are required for optimal pol delta activity. This supports the hypothesis that the interaction between pol delta and PCNA is a divalent one that involves p12 and p68. We propose a model in which pol delta interacts with PCNA via at least two of its subunits, and one in which p12 could play a role in stabilizing the overall pol delta-PCNA complex as well as pol delta itself.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14748-55
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Functional roles of p12, the fourth subunit of human DNA polymerase delta.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural