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Detailed structural-functional analysis of the Kr??ppel-like factor 16 (KLF16) transcription factor reveals novel mechanisms for silencing Sp/KLF sites involved in metabolism and endocrinology. J Biol Chem 2012 Mar 02;287(10):7010-25

Date

12/29/2011

Pubmed ID

22203677

Pubmed Central ID

PMC3293586

DOI

10.1074/jbc.M111.266007

Scopus ID

2-s2.0-84863280739   32 Citations

Abstract

Kr??ppel-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 (32)P 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.

Author List

Daftary GS, Lomberk GA, Buttar NS, Allen TW, Grzenda A, Zhang J, Zheng Y, Mathison AJ, Gada RP, Calvo E, Iovanna JL, Billadeau DD, Prendergast FG, Urrutia R

Authors

Gwen Lomberk PhD Professor in the Surgery department at Medical College of Wisconsin
Angela Mathison PhD Assistant Professor in the Surgery department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Active Transport, Cell Nucleus
Amino Acid Substitution
Chromatin
Feeder Cells
Female
Gene Silencing
Gonadal Steroid Hormones
Humans
Kruppel-Like Transcription Factors
Mutation, Missense
Nuclear Localization Signals
Phosphorylation
Protein Structure, Tertiary
Reproduction
Response Elements
Sin3 Histone Deacetylase and Corepressor Complex
Structure-Activity Relationship
Uterus