Detailed Structural-Functional Analysis of the Krüppel-like Factor 16 (KLF16) Transcription Factor Reveals Novel Mechanisms for Silencing Sp/KLF Sites Involved in Metabolism and Endocrinology*
| Autor: | Gwen Lomberk, Angela Mathison, Adrienne Grzenda, Jin-San Zhang, Thomas Wesley Allen, Ezequiel Calvo, Navtej S. Buttar, Juan L. Iovanna, Ye Zheng, Franklyn G. Prendergast, Gaurang S. Daftary, Raul Urrutia, Daniel D. Billadeau, R. Gada |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Gene isoform
Kruppel-like Factor (KLF) Nuclear Localization Signals Active Transport Cell Nucleus Kruppel-Like Transcription Factors Mutation Missense Biology Response Elements Biochemistry Sp1 03 medical and health sciences Structure-Activity Relationship 0302 clinical medicine Endocrinology Gene silencing Humans Gene Regulation Gene Silencing Phosphorylation Gonadal Steroid Hormones Molecular Biology Transcription factor 030304 developmental biology Genetics 0303 health sciences Reproduction Uterus Feeder Cells Cell Biology Chromatin Cell biology Protein Structure Tertiary Sin3 Histone Deacetylase and Corepressor Complex Histone Metabolism Amino Acid Substitution 030220 oncology & carcinogenesis biology.protein Female Histone deacetylase Sin3 Function (biology) |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X 0021-9258 |
| Popis: | Background: KLF16 is the least characterized family member of recently described metabolic regulators. Results: We extensively characterize mechanisms of DNA binding and chromatin coupling used by KLF16 to regulate metabolic gene expression. Conclusion: KLF16 is a novel regulator of metabolic genes by regulatable coupling to Sin3-histone deacetylase complexes. Significance: This knowledge reveals key mechanisms used by KLF16 as a regulator of metabolic gene expression. Krüppel-like factor (KLF) proteins have elicited significant attention due to their emerging key role in metabolic and endocrine diseases. Here, we extend this knowledge through the biochemical characterization of KLF16, unveiling novel mechanisms regulating expression of genes involved in reproductive endocrinology. We found that KLF16 selectively binds three distinct KLF-binding sites (GC, CA, and BTE boxes). KLF16 also regulated the expression of several genes essential for metabolic and endocrine processes in sex steroid-sensitive uterine cells. Mechanistically, we determined that KLF16 possesses an activation domain that couples to histone acetyltransferase-mediated pathways, as well as a repression domain that interacts with the histone deacetylase chromatin-remodeling system via all three Sin3 isoforms, suggesting a higher level of plasticity in chromatin cofactor selection. Molecular modeling combined with molecular dynamic simulations of the Sin3a-KLF16 complex revealed important insights into how this interaction occurs at an atomic resolution level, predicting that phosphorylation of Tyr-10 may modulate KLF16 function. Phosphorylation of KLF16 was confirmed by in vivo 32P incorporation and controlled by a Y10F site-directed mutant. Inhibition of Src-type tyrosine kinase signaling as well as the nonphosphorylatable Y10F mutation disrupted KLF16-mediated gene silencing, demonstrating that its function is regulatable rather than constitutive. Subcellular localization studies revealed that signal-induced nuclear translocation and euchromatic compartmentalization constitute an additional mechanism for regulating KLF16 function. Thus, this study lends insights on key biochemical mechanisms for regulating KLF sites involved in reproductive biology. These data also contribute to the new functional information that is applicable to understanding KLF16 and other highly related KLF proteins. |
| Databáze: | OpenAIRE |
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