KLF4 Human, His
Description
Molecular Structure of KLF4
KLF4 contains several critical domains that govern its function:
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Zinc finger motifs (amino acids 384–390): Mediate DNA binding to CACCC motifs and act as nuclear localization signals (NLS) .
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Transcriptional activation domain (residues 91–117): Rich in proline/serine, essential for gene activation .
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Repression domain (residues 181–388): Facilitates gene silencing .
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PEST domain: Regulates protein degradation via ubiquitination; mutations here are linked to lymphoma and leukemia .
Structural studies reveal that KLF4’s zinc finger integrity is crucial for nuclear localization and DNA-binding activity .
Functional Roles in Cellular Processes
KLF4 regulates diverse pathways:
Stem Cell Maintenance
As a Yamanaka factor, KLF4 maintains pluripotency in embryonic stem cells by activating epithelial genes (e.g., Oct4) and recruiting chromatin-modifying enzymes .
Cell Cycle and Differentiation
Immune Regulation
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Suppresses Th17 differentiation and IL-17 production in CD4+ T cells .
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Modulates macrophage polarization and HMGB1 expression in inflammatory responses .
Cancer
KLF4 exhibits context-dependent roles:
Hematologic Disorders
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β-thalassemia: KLF4 knockdown increases fetal hemoglobin (HbF) by 1.5–5.0% via HBG upregulation, independent of BCL11A/LRF .
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α-thalassemia: KLF4 suppression elevates embryonic ζ-globin (HBZ), suggesting therapeutic potential .
Small-Molecule Modulators
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KLF4 inducers: Enhance resolution of pulmonary fibrosis by promoting fibroblast quiescence .
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KLF4 inhibitors: Under investigation for cancers with oncogenic KLF4 activity (e.g., HNSCC) .
Gene Therapy Approaches
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Adenoviral KLF4 delivery (Ad-KLF4) reduces lung tumor growth by 60% in murine models .
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CRISPR/Cas9-mediated KLF4 editing modulates HbF levels in erythroid progenitor cells .
Research Applications of Recombinant KLF4 (His-Tagged)
His-tagged KLF4 is widely used for:
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Chromatin immunoprecipitation (ChIP): Identifies KLF4-binding sites (e.g., hTERT promoter in lung cancer) .
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Protein interaction studies: KLF4 binds p300/CBP to regulate acetylation-dependent transcription .
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In vitro differentiation assays: Essential for generating induced pluripotent stem cells (iPSCs) .
Key Research Findings
Product Specs
Product Science Overview
Kruppel-Like Factor 4 (KLF4) is a transcription factor that belongs to the Kruppel family of zinc finger proteins. It plays a crucial role in regulating various cellular processes, including differentiation, proliferation, and apoptosis. KLF4 is particularly important in maintaining the barrier function of the skin and in the regulation of the cell cycle, especially in response to DNA damage by mediating the tumor suppressor gene p53 .
The human recombinant KLF4 protein with a His tag is a denatured recombinant protein that includes a N-terminal His-tag and corresponds to the amino acids 11-395 of the human KLF4 protein . This recombinant protein is produced in Escherichia coli (E. coli) and has a molecular weight of approximately 44.2 kDa . The His tag facilitates the purification of the protein using affinity chromatography techniques.
The recombinant KLF4 protein is typically prepared using bacterial expression systems, such as E. coli. The gene encoding KLF4 is cloned into an expression vector that includes a sequence for the His tag. This vector is then introduced into E. coli cells, which express the recombinant protein. The protein is subsequently purified using affinity chromatography, which exploits the interaction between the His tag and a nickel or cobalt resin .
KLF4 functions as both an activator and a repressor of transcription. It binds to the 5’-CACCC-3’ core sequence in the promoter regions of target genes, regulating their expression. KLF4 is involved in various biological processes, including the maintenance of embryonic stem cells, prevention of their differentiation, and the establishment of the barrier function of the skin . It also plays a role in the differentiation of epithelial cells and may be involved in skeletal and kidney development .
The recombinant KLF4 protein with a His tag is widely used in research to study its function and regulation. It is particularly useful in experiments involving protein-protein interactions, DNA-binding studies, and the investigation of its role in various cellular processes. The His tag allows for easy purification and detection of the protein, making it a valuable tool in molecular biology and biochemistry research .
