Structural and functional characterization of an atypical activation domain in erythroid Krüppel-like factor (EKLF)

Abstract

Erythroid Krüppel-like factor (EKLF) plays an important role in erythroid development by stimulating β-globin gene expression. We have examined the details by which the minimal transactivation domain (TAD) of EKLF (EKLFTAD) interacts with several transcriptional regulatory factors. We report that EKLFTAD displays homology to the p53TAD and, like the p53TAD, can be divided into two functional subdomains (EKLFTAD1 and EKLFTAD2). Based on sequence analysis, we found that EKLFTAD2 is conserved in KLF2, KLF4, KLF5, and KLF15. In addition, we demonstrate that EKLFTAD2 binds the amino-terminal PH domain of the Tfb1/p62 subunit of TFIIH (Tfb1PH/p62PH) and four domains of CREB-binding protein/ p300. The solution structure of the EKLFTAD2/Tfb1PH complex indicates that EKLFTAD2 binds Tfb1PH in an extended conformation, which is in contrast to the α-helical conformation seen for p53TAD2 in complex with Tfb1PH. These studies provide detailed mechanistic information into EKLFTAD functions as well as insights into potential interactions of the TADs of other KLF proteins. In addition, they suggest that not only have acidic TADs evolved so that they bind using different conformations on a common target, but that transitioning from a disordered to a more ordered state is not a requirement for their ability to bind multiple partners.hematopoiesis | NMR spectroscopy | transcriptional activators | intrinsically unstructured domain | transcription factor IIE

Kruppel-like factor 15 is critical for vascular inflammation

“…Second, we defined a specific 15-amino acid region within KLF15 that mediates the interaction with p300. Intriguingly, as recently pointed out by Omichinski and colleagues, this motif, which subserves p300 interaction, is common to p53 as well as to several KLFs (KLF1, 2, 4, 5, and 15) (35). Consequently, competition between KLF1/2/4/5/15 and p53 for p300 may provide a mechanism by which these KLFs can regulate major cellular processes such as survival and adaptation to genotoxic stress.…”

“…To determine the structural basis for KLF15 and p300 interaction, we took advantage of a recent finding that a specific motif within KLF1 mediates interaction with p300 (35). Since KLF15 also contains the same motif, we posited that this region may mediate interaction with p300.…”

Kruppel-like Factor 15 Is a Critical Regulator of Cardiac Lipid Metabolism

“…We were intrigued by a recent biophysical study that demonstrated significant similarity between the p300-interacting domain of p53 and a homologous domain within the erythroid-specific KLF family member, EKLF/KLF1 (46). Indeed, inspection of the KLF15 gene revealed a putative p300-interacting transactivation domain (Fig.…”

Krüppel-like factors in mammalian stem cells and development

“…2 The specificity of KLF-mediated transcriptional activation is defined mostly by their N-terminal sequences. KLF1,2,4,5,6,8 and 15 (the latter by homology only) possess a transactivation domain (TAD) within their N-terminal regions (Chen and Bieker, 1996;Conkright et al, 1999Conkright et al, , 2001Kojima et al, 1997;Koritschoner et al, 1997;Lahiri and Zhao, 2012;Mas et al, 2011;Ratziu et al, 1998;van Vliet et al, 2000;Wani et al, 1999a). KLF1 has a very well-defined and essential TAD in its first 100 amino acids (Chen and Bieker, 1996).…”

“…KLF1 has a very well-defined and essential TAD in its first 100 amino acids (Chen and Bieker, 1996). It has been shown that the KLF1 TAD can be divided into two regions -TAD1 and TAD2 -and that the latter is also conserved in KLF2, 4, 5 and 15 (Mas et al, 2011). In addition, a repression domain adjacent to the activation domain has been identified in KLF2 and KLF4 (Conkright et al, 2001;Geiman et al, 2000;Wani et al, 1999a).…”