The diverse functions of Krüppel-like factors 4 and 5 in epithelial biology and pathobiology.
The Krüppel-like factors (KLFs) comprise a family of evolutionarily conserved zinc finger transcription factors that regulate numerous biological processes including proliferation, differentiation, development and apoptosis. KLF4 and KLF5 are two closely related members of this family and are both highly expressed in epithelial tissues. In the intestinal epithelium, KLF4 is expressed in terminally differentiated epithelial cells at the villus borders of the mucosa and inhibits cell growth, while KLF5 is expressed in proliferating epithelial cells at the base of the intestinal crypts and promotes cell growth. KLF4 and KLF5 respond to a myriad of external stress stimuli and are likely involved in restoring cellular homeostasis following exposure to stressors. Confirming their importance in maintaining tissue integrity, KLF4 and KLF5 are both dysregulated in various types of cancer. Here we review the recent advances in defining the physiological and pathobiological roles of KLF4 and KLF5, focusing on their functions in the intestinal epithelium.
McConnell
Beth B
BB
Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA.
Ghaleb
Amr M
AM
Nandan
Mandayam O
MO
Yang
Vincent W
VW
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism / Q000473:pathology / Q000502:physiology; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism*; D009369:Neoplasms / Q000378:metabolism
C000715467:KLF4 protein, human; C492214:KLF5 protein, human; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors