1: Eur J Cell Biol. 2002 Jun;81(6):323-34. 

Human Kruppel-like factor5/KLF5: synergy with NF-kappaB/Rel factors and
expression in human skin and hair follicles.

Sur I, Unden AB, Toftgard R.

Department of Biosciences at Novum, Center for Nutrition and Toxicology,
Karolinska Institutet, Huddinge, Sweden. inderpreet.sur@cnt.ki.se

In this report we describe the identification of Kruppel-like factor 5
(KLF5/BTEB2) in a yeast one-hybrid screen using a keratinocyte-specific,
NF-kappaB binding site as bait. The KLF5 cDNA encodes a larger protein of 457 aa
rather than the earlier reported protein of 209 aa. The full-length KLF5
functions as a transactivator in HepG2 cells, and the stimulation of cells with
12-0-tetradecanoylphorbol-13-acetate (TPA) can modulate its transcriptional
activity. Overexpression of KLF5 leads to an increase in the TPA response from
VLTRE, a TPA-inducible enhancer element that shows keratinocyte specificity with
respect to Rel/NF-kappaB binding. The KLF5-mediated transcriptional increase is
not observed in the presence of overexpressed NF-kappaB inhibitor, IkappaBalpha.
Cotransfection of KLF5 and the p65 subunit of NF-kappaB, results in a
synergistic transactivation of the VLTRE-luciferase reporter. The KLF5 mRNA and
the protein is expressed in keratinocytes and throughout the adult human
epidermis. Its expression is especially strong in the matrix and the inner root
sheath cuticle layer of the hair follicle, sebaceous glands and sweat glands.
Considering the TPA-responsiveness and expression pattern, we propose that KLF5
like another member of its family KLF4/GKLF may play an important role in skin
morphogenesis and carcinogenesis potentially via its interaction with NF-kappaB
factors.

PMID: 12113473 [PubMed - indexed for MEDLINE]


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