Source:http://linkedlifedata.com/resource/pubmed/id/15175336
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
31
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| pubmed:dateCreated |
2004-7-26
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| pubmed:abstractText |
Myb transcription factors, which contain three imperfect repeats in the Myb domain, are evolutionarily conserved members of the Myb superfamily. Vertebrate Myb proteins with three repeats, c-Myb, A-Myb, and BMyb, play important roles at the G(1)/S transition in the cell cycle. In plants, this type of Myb protein controls the G(2)/M phase by activating or repressing the transcription of cyclin B genes and a variety of other G(2)/M phase-specific genes. In tobacco, two genes for Myb activators, NtmybA1 and NtmybA2, are transcriptionally controlled and are expressed specifically at the G(2)/M phase. As we showed here, in addition to the control at the transcriptional level, activity of NtmybA2 is also controlled at the post-translational level. We found that the transactivation potential of NtmybA2 is repressed by a regulatory domain located at its carboxyl terminus and that specific classes of cyclins A and B enhanced NtmybA2 activity possibly by relieving this inhibitory effect. Mutations at the 20 potential sites of phosphorylation by cyclin-dependent kinase (CDK) in NtmybA2 blocked the enhancing effects of the cyclins on NtmybA2 activity. Recombinant NtmybA2 was phosphorylated in vitro by a CDK fraction prepared from tobacco BY2 cells. The kinase activity for NtmybA2 in the CDK fraction was cell cycle-regulated in BY2 cells, peaking at the G(2)/M phase when the level of transcripts of cyclin B is maximal. Taken together, our data suggest that NtmybA2 is phosphorylated by a specific cyclin/CDK complex(es) at G(2)/M and that this phosphorylation removes the inhibitory effect of its C-terminal region, thereby activating NtmybA2 specifically at G(2)/M.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Cyclin A,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclin B,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclins,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Complementary,
http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-myb,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins
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| pubmed:status |
MEDLINE
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| pubmed:month |
Jul
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| pubmed:issn |
0021-9258
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
30
|
| pubmed:volume |
279
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| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
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| pubmed:pagination |
32979-88
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| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:15175336-Binding Sites,
pubmed-meshheading:15175336-Cyclin A,
pubmed-meshheading:15175336-Cyclin B,
pubmed-meshheading:15175336-Cyclins,
pubmed-meshheading:15175336-DNA, Complementary,
pubmed-meshheading:15175336-G2 Phase,
pubmed-meshheading:15175336-Genes, Reporter,
pubmed-meshheading:15175336-Mitosis,
pubmed-meshheading:15175336-Mutation,
pubmed-meshheading:15175336-Phosphorylation,
pubmed-meshheading:15175336-Plasmids,
pubmed-meshheading:15175336-Protein Processing, Post-Translational,
pubmed-meshheading:15175336-Protein Structure, Tertiary,
pubmed-meshheading:15175336-Proto-Oncogene Proteins c-myb,
pubmed-meshheading:15175336-Recombinant Proteins,
pubmed-meshheading:15175336-Time Factors,
pubmed-meshheading:15175336-Tobacco,
pubmed-meshheading:15175336-Transcription, Genetic,
pubmed-meshheading:15175336-Transcriptional Activation,
pubmed-meshheading:15175336-Transfection
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| pubmed:year |
2004
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| pubmed:articleTitle |
Mitotic cyclins stimulate the activity of c-Myb-like factors for transactivation of G2/M phase-specific genes in tobacco.
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| pubmed:affiliation |
Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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