Mouse Wee1 Gene Is Repressed by Krüppel-Like Factor 3 (KLF3) via Interaction with Multiple Upstream Elements

Wee1 protein kinase represses CDK1 required for G2/M transition. The mouse wee1 promoter contains multiple CACCC-boxes between − 306 and + 1 that can bind to Krüppel-like factor 3 (KLF3) transcriptional repressor. We found that increasing amounts of intracellular KLF3 decreased the amount of wee1 mRNA. A promoter reporter assay demonstrated that wee1 promoter activity was repressed by KLF3 overexpression. Elimination of the first and fourth CACCC-boxes suppressed KLF3-governed transcriptional repression. A gel-shift assay demonstrated that KLF3 binds to the first, third, and fourth CACCC-boxes with various strengths. Moreover, KLF3 was suggested to interact with the wee1 regulatory region in a physiological condition. Therefore, we concluded that KLF3 is a transcriptional repressor for wee1 gene. In a previous study, we demonstrated that TBP-like protein (TLP) inhibits wee1 promoter function. In this study, we found that the chromosomal wee1 gene is also down-regulated by KLF3. Since KLF3-repressed wee1 promoter function was further inhibited by TLP overexpression regardless of the inhibition degree of KLF3, we propose that TLP and KLF3 repress wee1 promoter independently.

► We examine wee1 gene regulation by KLF3 transcription factor.
► Endogenous wee1 gene is down-regulated by KLF3.
► KLF3 KLF3 represses wee1 promoter through binding to CACCC elements.
► KLF3 interacts with a regulatory region of the chromosomal wee1 gene.
► KLF3-repressed wee1 promoter is further inhibited by TBP-like protein.