Repression of p15INK4b expression by Myc through association with Miz-1.
Deregulated expression of c-myc can induce cell proliferation in established cell lines and in primary mouse embryonic fibroblasts (MEFs), through a combination of both transcriptional activation and repression by Myc. Here we show that a Myc-associated transcription factor, Miz-1, arrests cells in G1 phase and inhibits cyclin D-associated kinase activity. Miz-1 upregulates expression of the cyclin-dependent kinases (CDK) inhibitor p15INK4b by binding to the initiator element of the p15INK4b promoter. Myc and Max form a complex with Miz-1 at the p15 initiator and inhibit transcriptional activation by Miz-1. Expression of Myc in primary cells inhibits the accumulation of p15INK4b that is associated with cellular senescence; conversely, deletion of c-myc in an established cell line activates p15INK4b expression. Alleles of c-myc that are unable to bind to Miz-1 fail to inhibit accumulation of p15INK4b messenger RNA in primary cells and are, as a consequence, deficient in immortalization.
Staller
P
P
Institute of Molecular Biology and Tumour Research, Emil Mannkopff Strabetae 2, 35033 Marburg, Germany.
Peukert
K
K
Kiermaier
A
A
Seoane
J
J
Lukas
J
J
Karsunky
H
H
Möröy
T
T
Bartek
J
J
Massagué
J
J
Hänel
F
F
Eilers
M
M
D016475:3T3 Cells; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins; D016335:Zinc Fingers
C493966:CDKN2B protein, human; D002352:Carrier Proteins; C493968:Cdkn2b protein, mouse; C493969:Cdkn2b protein, rat; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004268:DNA-Binding Proteins; D051741:Kruppel-Like Transcription Factors; D009687:Nuclear Proteins; D016271:Proto-Oncogene Proteins c-myc; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C107961:ZBTB17 protein, human