S. Leverrier, E. Cinato, C. Paul, J. Derancourt, M. Bemark, T. Leanderson, C. Legraverend
Purification and Cloning of Type A/B hnRNP Proteins Involved in Transcriptional Activation from the Rat spi 2 Gene GAGA Box
The GAGA box of the rat serine protease inhibitor 2
(spi 2) genes not only acts as a basal promoter element,
but also mediates transcriptional activation by
growth hormone and interleukin-6. The GAGA box is
separated from the TATA box by only 12 bp, and this
close association is required for efficient transcription.
Hence, the GAGA box may influence transcription
efficiency through interactions between GAGA box
binding proteins and some components of the RNA
polymerase II complex. Here we report the cloning of
two GAGA box-binding proteins termed p38 and p40,
that belong to the type A/B heterogeneous nuclear
ribonucleoprotein subgroup. GAGA box mutations
that diminish the affinity for p38 and p40 decrease
basal and GH-induced reporter gene expression.
Furthermore, nuclear extracts depleted of p38 and p40
can no longer support GAGA box-dependent in vitro
transcription. Therefore, two polypeptides previously
assigned to a family of RNA processing proteins also
act as DNA-binding, promoter-specific transcription
factors.
Biological Chemistry, Walter de Gruyter
Print ISSN: 1431-6730
Volume: 381, 11/2000
Pages: 1031 - 1040
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