Reconstitution of transcriptional activation domains by reiteration of short peptide segments reveals the modular organization of a glutamine-rich activation domain

Tanaka, M., Herr, W. (September 1994) Reconstitution of transcriptional activation domains by reiteration of short peptide segments reveals the modular organization of a glutamine-rich activation domain. Mol Cell Biol, 14 (9). pp. 6056-67. ISSN 0270-7306 (Print)

URL: http://www.ncbi.nlm.nih.gov/pubmed/8065339
DOI: 10.1128/MCB.14.9.6056

Abstract

The POU domain activator Oct-2 contains an N-terminal glutamine-rich transcriptional activation domain. An 18-amino-acid segment (Q18III) from this region reconstituted a fully functional activation domain when tandemly reiterated and fused to either the Oct-2 or GAL4 DNA-binding domain. A minimal transcriptional activation domain likely requires three tandem Q18III segments, because one or two tandem Q18III segments displayed little activity, whereas three to five tandem segments were active and displayed increasing activity with increasing copy number. As with natural Oct-2 activation domains, in our assay a reiterated activation domain required a second homologous or heterologous activation domain to stimulate transcription effectively when fused to the Oct-2 POU domain. These results suggest that there are different levels of synergy within and among activation domains. Analysis of reiterated activation domains containing mutated Q18III segments revealed that leucines and glutamines, but not serines or threonines, are critical for activity in vivo. Curiously, several reiterated activation domains that were inactive in vivo were active in vitro, suggesting that there are significant functional differences in our in vivo and in vitro assays. Reiteration of a second 18-amino-acid segment from the Oct-2 glutamine-rich activation domain (Q18II) was also active, but its activity was DNA-binding domain specific, because it was active when fused to the GAL4 than to the Oct-2 DNA-binding domain. The ability of separate short peptide segments derived from a single transcriptional activation domain to activate transcription after tandem reiteration emphasizes the flexible and modular nature of a transcriptional activation domain.

Item Type: Paper
Uncontrolled Keywords: Amino Acid Sequence Base Sequence Comparative Study DNA-Binding Proteins/ chemistry Enhancer Elements (Genetics) Hela Cells Humans Molecular Sequence Data Mutagenesis, Site-Directed Octamer Transcription Factor-2 Oligonucleotide Probes/chemistry Research Support, U.S. Gov't, P.H.S. Sequence Alignment Sequence Homology, Amino Acid Structure-Activity Relationship Transcription Factors/ chemistry
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > transcription
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > DNA binding protein
CSHL Authors:
Communities: CSHL labs > Herr lab
Depositing User: Matt Covey
Date: September 1994
Date Deposited: 05 Aug 2015 19:30
Last Modified: 05 Aug 2015 19:30
PMCID: PMC359132
Related URLs:
URI: http://repository.cshl.edu/id/eprint/31449

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