Kruppel-like factor 4 (KLF4)

Kruppel-like factor 4 (KLF4) is a zinc-finger transcription factor that plays a critical role in regulating cellular proliferation, differentiation, and the maintenance of tissue homeostasis. In epithelial tissues, KLF4 is a master regulator of the barrier function, specifically through the transcriptional activation of tight junction proteins such as Claudin-1, Occludin, and ZO-1. By maintaining the integrity of these junctions, KLF4 prevents paracellular leakage and protects against environmental insults in the gut, skin, and corneal epithelium. In the context of disease, KLF4 exhibits a complex, context-dependent role; it often functions as a tumor suppressor in the gastrointestinal tract but can act as an oncogene in certain breast and squamous cell carcinomas. Therapeutic targeting of KLF4 is of significant interest in regenerative medicine and oncology, although its status as a Yamanaka factor—essential for inducing pluripotency—necessitates careful modulation to avoid unintended dedifferentiation or tumorigenesis. Current pharmacological approaches often focus on indirect modulation of KLF4 expression or activity through signaling pathways like TGF-beta or MAPK to restore barrier function or inhibit cancer progression.

Other names

Gut-enriched krueppel-like factorGKLFEpithelial zinc finger protein EZFEZF

KLF4 acts as a transcriptional regulator that binds to GC-rich elements in the promoters of target genes, such as claudins and occludin, to modulate the assembly and stability of tight junction complexes.