Interaction between the pura and E2F-1 transcription factors.
BACKGROUND
Cell proliferation is regulated by E2F-1 which facilitates expression of genes involved in entry into S-phase. Release of E2F-1 from binding partners, e.g. pRb, is critical for G1/S progression. However ectopic E2F-1 overexpression activates p53 and inhibits growth. Previously, the multifunctional Pura protein was found to bind to E2F-1 and inhibit E2F-1 transcriptional activity.


METHODS
Pura deletion mutants were assayed for: in vitro binding to E2F-1, inhibition of E2F-1-induced promoter activation and effects on cell proliferation. Two RNA species with specific binding to E2F-1 and Pura were analyzed for their effects on E2F-1/Pura binding and cell growth.


RESULTS
The N-terminal 72 amino acids of Pura were involved in E2F-1 binding, inhibition of promoter activation by E2F-1 and reversal of E2F-mediated growth inhibition. The RNA species disrupted Pura/E2F-1 interaction and affected cell growth.


CONCLUSIONS
E2F-1/Pura interaction has a role in the control of cell proliferation.
Darbinian
Nune
N
Center for Neurovirology and Cancer Biology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA.
White
Martyn K
MK
Gallia
Gary L
GL
Amini
Shohreh
S
Rappaport
Jay
J
Khalili
Kamel
K
D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008527:Medulloblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D015347:RNA Probes / Q000378:metabolism; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015533:Transcriptional Activation; D014162:Transfection
D018797:Cell Cycle Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; C501130:PURA protein, human; D015347:RNA Probes; D014157:Transcription Factors; D013762:Tetrahydrofolate Dehydrogenase