The Oct-2 glutamine-rich and proline-rich activation domains can synergize with each other or duplicates of themselves to activate transcription.
Open Access
- 1 September 1994
- journal article
- Published by Taylor & Francis in Molecular and Cellular Biology
- Vol. 14 (9), 6046-6055
- https://doi.org/10.1128/mcb.14.9.6046
Abstract
The B-cell POU homeodomain protein Oct-2 contains two transcriptional activation domains, one N terminal and the other C terminal of the central DNA-binding POU domain. The synergistic action of these two activation domains makes Oct-2 a more potent activator of mRNA promoters than the related broadly expressed octamer motif-binding protein Oct-1, which contains an N-terminal but not a C-terminal Oct-2-like activation domain. Both Oct-2 mRNA promoter activation domains were delineated by truncation analysis: the N-terminal Q domain is a 66-amino-acid region rich in glutamines, and the C-terminal P domain is a 42-amino-acid region rich in prolines. The Q and P domains synergized with each other or duplicates of themselves, independently of their N-terminal or C-terminal position relative to the POU domain. The C-terminal P domain, which differentiates Oct-2 from Oct-1, also activated transcription in conjunction with the heterologous GAL4 DNA-binding domain. Oct-2 thus contains three modular functional units, the DNA-binding POU domain and the two P and Q activation domains. An electrophoretic mobility shift assay with a variety of these Oct-2 activators revealed a distinct complex called QA that was dependent on the presence of an active glutamine-rich activation domain and migrated more slowly than the Oct-2-DNA complexes. Formation of the QA complex is consistent with interaction of the glutamine-rich activation domains with a regulatory protein important for the process of transcriptional activation.Keywords
This publication has 27 references indexed in Scilit:
- Conserved motifs in Fos and Jun define a new class of activation domain.Genes & Development, 1992
- Mechanism of action of an acidic transcriptional activator in vitroCell, 1991
- A novel mediator between activator proteins and the RNA polymerase II transcription apparatusCell, 1990
- Mechanism of transcriptional activation by Sp1: Evidence for coactivatorsCell, 1990
- An amino-terminal fragment of GAL4 binds DNA as a dimerJournal of Molecular Biology, 1989
- How eukaryotic transcriptional activators workNature, 1988
- Cooperativity and hierarchical levels of functional organization in the SV40 enhancerCell, 1988
- The c-fos serum response element responds to protein kinase C-dependent and -independent signals but not to cyclic AMP.Genes & Development, 1988
- The yeast UASG is a transcriptional enhancer in human hela cells in the presence of the GAL4 trans-activatorCell, 1988
- An octamer oligonucleotide upstream of a TATA motif is sufficient for lymphoid-specific promoter activityNature, 1987