Expression of the Oct-1 Transcription Factor and Characterization of Its Interactions with the Bob1 Coactivator
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- 作者：Larissa Lee ; Elliott Stollar ; JuFang Chang ; J. Gü ; nter Grossmann ; Ronan O'Brien ; John Ladbury ; Brian Carpenter ; Stefan Roberts ; and Ben Luisi
- 刊名：Biochemistry
- 出版年：2001
- 出版时间：June 5, 2001
- 年：2001
- 卷：40
- 期：22
- 页码：6580 - 6588
- 全文大小：185K
- 年卷期：v.40,no.22(June 5, 2001)
- ISSN：1520-4995
文摘
The Oct-1 transcription factor regulates a variety of tissue-specific and general housekeepinggenes by recruiting specialized coactivators of transcription. It acts synergistically with the B-cell-specificcoactivator Bob1 (OCA-B, OBF-1) to stimulate transcription of immunoglobulin genes. To analyze Oct-1's interactions with Bob1 and other regulatory proteins, we have overexpressed and purified differentfunctional domains of the recombinant proteins. A version of Oct-1 that encompasses the amino-terminalactivation region and the POU DNA-binding domain was extensively characterized (Oct
C1; comprisingresidues 1-445). Using an in vitro transcription assay, we demonstrate that this fragment is sufficientand necessary to stimulate transcription from an immunoglobulin promoter with Bob1. It also coactivatesfrom the herpes simplex virus ICPO promoter element in the presence of VP16. Using a range ofspectroscopic and biophysical techniques, we demonstrate that the activation domains of Oct-1 and Bob1have little globular structure and that they do not physically interact. Thus, their functional synergy islikely to arise by the co-recruitment of common factors as part of a larger regulatory assembly. We proposea hypothesis to explain why the activation domains of these and other transcription factors of metazoanshave little if any intrinsic structure.
C1; comprisingresidues 1-445). Using an in vitro transcription assay, we demonstrate that this fragment is sufficientand necessary to stimulate transcription from an immunoglobulin promoter with Bob1. It also coactivatesfrom the herpes simplex virus ICPO promoter element in the presence of VP16. Using a range ofspectroscopic and biophysical techniques, we demonstrate that the activation domains of Oct-1 and Bob1have little globular structure and that they do not physically interact. Thus, their functional synergy islikely to arise by the co-recruitment of common factors as part of a larger regulatory assembly. We proposea hypothesis to explain why the activation domains of these and other transcription factors of metazoanshave little if any intrinsic structure.