Three classes of mammalian transcription activation domain stimulate transcription in Schizosaccharomyces pombe

Abstract

Representatives of three distinct classes of mammalian protein domain activating RNA polymerase II were fused to the yeast GAL4p DNA‐binding domain. The resulting fusion proteins were tested in the fission yeast Schizosaccharomyces pombe for their ability to activate transcription of different reporter constructs containing GAL4‐binding sites in positions close to or far from the TATA box. The acidic‐rich activation domain of VP16 stimulates transcription in S.pombe from proximal and distal positions, suggesting that the mechanism of activation is conserved from man to budding and fission yeasts. Unlike in Saccharomyces cerevisiae, the glutamine‐rich activation domains of Sp1, Oct1 and Oct2 activate transcription in S.pombe when tested in a proximal TATA box context. Similarly to mammalian cells, these domains are inactive or weakly active when tested in a distal position. Moreover, the proline‐rich activation domains of AP‐2 and CTF/NF1 display strong transcriptional activities from a TATA box‐proximal position, and weak activities when tested in a remote position. Consequently, proline‐rich and glutamine‐rich activation domains act differently in S.cerevisiae and mammalian cells, but similarly in S.pombe and mammalian cells.

Formation of a Carboxy-Terminal Domain Phosphatase (Fcp1)/TFIIF/RNA Polymerase II (pol II) Complex in Schizosaccharomyces pombe Involves Direct Interaction between Fcp1 and the Rpb4 Subunit of pol II

“…Otherwise, the S. cerevisiae Fcp1 does not form a complex with pol II. We used the fission yeast S. pombe because the transcriptional mechanism is more similar to that of higher eukaryotes (40,55,60), all the pol II subunit genes have been cloned (4,5,29,47,58,59,60,63,64), and the subunit-subunit interactions have been well characterized (31,32,33). A large complex of pol II holoenzyme has been isolated from S. pombe (66).…”

Arabidopsis GLUTAMINE-RICH PROTEIN23Is Essential for Early Embryogenesis and Encodes a Novel Nuclear PPR Motif Protein That Interacts with RNA Polymerase II Subunit III

“…There is a relatively conserved transcriptional activation function for the Gln-rich domain from yeast to human (Dynan and Tjian, 1983;Remacle et al, 1997;Escher et al, 2000;Petcherski and Kimble, 2000;Freiman and Tjian, 2002). This might be true for GRP23 as well.…”

“…Gln-rich domains represent one of the three classes of protein domains present in proteins that regulate the expression of specific sets of genes by selectively interacting with a core component of the transcriptional machinery, such as TFIID and TAFIIs (Triezenberg, 1995;Remacle et al, 1997;Saluja et al, 1998). The sequences of Gln-rich proteins usually have very low homology, which makes it difficult to classify them.…”

hpttg, a human homologue of rat pttg, is overexpressed in hematopoietic neoplasms. Evidence for a transcriptional activation function of hPTTG

“…Several mammalian proteins containing acidic-rich and/or proline-rich activation domains have been shown to stimulate transcription in S. cerevisiae (Lech et al, 1988;Metzger et al, 1988;Sadowski et al, 1988;Schena and Yamamoto, 1988;Struhl, 1988) and in Schizosaccharomyces pombe (Remacle et al, 1997). The domain of hPTTG that shows transactivation capacity (amino acids 123 ± 202), although rich in proline, seems to belong to the acidicrich class since it contains 19% of acidic amino acids and has a net charge of 712.…”