Abstract:
:A cell-free nuclear replication system that is S-phase specific, that requires the activity of DNA polymerase alpha, and that is stimulated three- to eightfold by cytoplasmic factors from S-phase cells was used to examine the temporal specificity of chromosomal DNA synthesis in vitro. Temporal specificity of DNA synthesis in isolated nuclei was assessed directly by examining the replication of restriction fragments derived from the amplified 200-kilobase dihydrofolate reductase domain of methotrexate-resistant CHOC 400 cells as a function of the cell cycle. In nuclei prepared from cells collected at the G1/S boundary of the cell cycle, synthesis of amplified sequences commenced within the immediate dihydrofolate reductase origin region and elongation continued for 60 to 80 min. The order of synthesis of amplified restriction fragments in nuclei from early S-phase cells in vitro appeared to be indistinguishable from that in vivo. Nuclei prepared from CHOC 400 cells poised at later times in the S phase synthesized characteristic subsets of other amplified fragments. The specificity of fragment labeling patterns was stable to short-term storage at 4 degrees C. The occurrence of stimulatory factors in cytosol extracts was cell cycle dependent in that minimal stimulation was observed with early G1-phase extracts, whereas maximal stimulation was observed with cytosol extracts from S-phase cells. Chromosomal synthesis was not observed in nuclei from G1 cells, nor did cytosol extracts from S-phase cells induce chromosomal replication in G1 nuclei. In contrast to chromosomal DNA synthesis, mitochondrial DNA replication in vitro was not stimulated by cytoplasmic factors and occurred at equivalent rates throughout the G1 and S phases. These studies show that chromosomal DNA replication in isolated nuclei is mediated by stable replication forks that are assembled in a temporally specific fashion in vivo and indicate that the synthetic mechanisms observed in vitro accurately reflect those operative in vivo.
journal_name
Mol Cell Bioljournal_title
Molecular and cellular biologyauthors
Heintz NH,Stillman BWdoi
10.1128/mcb.8.5.1923subject
Has Abstractpub_date
1988-05-01 00:00:00pages
1923-31issue
5eissn
0270-7306issn
1098-5549journal_volume
8pub_type
杂志文章abstract::We analyzed epsilon-globin transcription in erythroid cells and in erythroid extracts to determine the requirements for enhancer-dependent expression of this gene. Mutations that abolished GATA-1 binding at a single position in the promoter prevented interaction with enhancers, whereas elimination of a second more dis...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.13.2.911
更新日期:1993-02-01 00:00:00
abstract::Immunoglobulin (Ig) mu heavy-chain gene enhancer activity is mediated by multiple DNA binding proteins. Mutations of several protein binding sites in the enhancer do not affect enhancer activity significantly. This feature, termed redundancy, is thought to be due to functional compensation of the mutated sites by othe...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.18.11.6870
更新日期:1998-11-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.7.3.1111
更新日期:1987-03-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.7.4.1450
更新日期:1987-04-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01406-12
更新日期:2013-06-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.4.12.2686
更新日期:1984-12-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.6.9.3150
更新日期:1986-09-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.9.3.1346
更新日期:1989-03-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00109-17
更新日期:2017-11-13 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01051-12
更新日期:2013-04-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章,评审
doi:10.1128/MCB.00232-20
更新日期:2020-08-28 00:00:00
abstract::The 3' regulatory region (3' RR) of the murine immunoglobulin heavy chain (IgH) locus contains multiple DNase I-hypersensitive (hs) sites. Proximal sites hs3A, hs1.2, and hs3B are located in an extensive palindromic region and together with hs4 are associated with enhancers involved in the expression and class switch ...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00233-08
更新日期:2008-10-01 00:00:00
abstract::Cks1 is an activator of the SCF(Skp2) ubiquitin ligase complex that targets the cell cycle inhibitor p27(Kip1) for degradation. The loss of Cks1 results in p27(Kip1) accumulation and decreased proliferation and inhibits tumorigenesis. We identify here a function of Cks1 in mammalian cell cycle regulation that is indep...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.06771-11
更新日期:2012-07-01 00:00:00
abstract::Transgenic mice containing a sheep metallothionein 1a-sheep growth hormone fusion gene exhibited low, tissue-specific basal levels of transgene mRNA expression, resulting in slightly elevated levels of circulating growth hormone that did not lead to a detectable increase in growth. After zinc stimulation, high levels ...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.9.12.5473
更新日期:1989-12-01 00:00:00
abstract::To identify novel genes that play critical roles in mediating bone morphogenetic protein (BMP) signal pathways, we performed a yeast two-hybrid screen using Smad1 as bait. A novel mouse Krüppel-type zinc finger protein, mZnf8, was isolated. Interactions between mZnf8 and Smad proteins were further analyzed with variou...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.22.21.7633-7644.2002
更新日期:2002-11-01 00:00:00
abstract::It has been hypothesized that protein factors may protect CpG islands from methyltransferase during development and that demethylation may involve protein-DNA interactions at demethylated sites. However, direct evidence has been lacking. In this study, demethylation at the EBNA-1 binding sites of the Epstein-Barr viru...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.19.1.46
更新日期:1999-01-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.4.7.1306
更新日期:1984-07-01 00:00:00
abstract::The protein tyrosine kinase c-Src is regulated by two intramolecular interactions. The repressed state is achieved through the interaction of the Src homology 2 (SH2) domain with the phosphorylated C-terminal tail and the association of the SH3 domain with a polyproline type II helix formed by the linker region betwee...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.02014-06
更新日期:2007-03-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.19.2.1369
更新日期:1999-02-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.22.6.1704-1713.2002
更新日期:2002-03-01 00:00:00
abstract::The Ace2p and Swi5p zinc finger proteins have nearly identical DNA-binding domains, yet in vivo they activate transcription of different genes, CTS1 and HO. We now demonstrate that Ace2p and Swi5p recognize sites in the CTS1 and HO promoters with the same affinities, raising the question of how promoter specificity is...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.16.4.1746
更新日期:1996-04-01 00:00:00
abstract::The short form (S1b) of the prolactin receptor (PRLR) silences prolactin-induced activation of gene transcription by the PRLR long form (LF). The functional and structural contributions of two intramolecular disulfide (S-S) bonds within the extracellular subdomain 1 (D1) of S1b to its inhibitory function on the LF wer...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.01716-08
更新日期:2009-05-01 00:00:00
abstract::A cDNA encoding a novel Krüppel-type zinc finger protein, FKLF, was cloned from fetal globin-expressing human fetal erythroid cells. The deduced polypeptide sequence composed of 512 amino acids revealed that, like Sp1 and EKLF, FKLF has three contiguous zinc fingers at the near carboxyl-terminal end. A long amino-term...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.19.5.3571
更新日期:1999-05-01 00:00:00
abstract::In the accompanying report (C. F. Webb, C. Das, S. Eaton, K. Calame, and P. Tucker, Mol. Cell. Biol. 11:5197-5205, 1991), we characterize B-cell-specific protein-DNA interactions at -500 and -200 bp upstream of the mu immunoglobulin heavy chain promoter whose abundances were increased by interleukin-5 plus antigen. Be...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.11.10.5206
更新日期:1991-10-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.8.9.3934
更新日期:1988-09-01 00:00:00
abstract::Poly(A)-binding protein (PABP) stimulates translation initiation by binding simultaneously to the mRNA poly(A) tail and eukaryotic translation initiation factor 4G (eIF4G). PABP activity is regulated by PABP-interacting (Paip) proteins. Paip1 binds PABP and stimulates translation by an unknown mechanism. Here, we desc...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.00738-08
更新日期:2008-11-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.18.4.2416
更新日期:1998-04-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/MCB.24.21.9527-9541.2004
更新日期:2004-11-01 00:00:00
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journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.14.11.7046
更新日期:1994-11-01 00:00:00
abstract::In this report we described the cloning and characterization of ADA5, a gene identified by resistance to GAL4-VP16-mediated toxicity. ADA5 binds directly to the VP16 activation domain but not to a transcriptionally defective VP16 double point mutant. Double mutants with mutations in ada5 and other genes (ada2 or ada3)...
journal_title:Molecular and cellular biology
pub_type: 杂志文章
doi:10.1128/mcb.16.6.3197
更新日期:1996-06-01 00:00:00