Transcription Factors/wnt

Lymphoid Enhancer Factor-1 (LEF-1) is a cell type-specific transcription factor and a member of the family of High Motility Group (HMG) domain proteins that recognizes a specific nucleotide sequence in the T cell receptor (TCR) alpha enhancer. The function of LEF-1 is dependent, in part, on the HMG domain that induces a sharp bend in the DNA helix, and on an activation domain that stimulates transcription only in the specific context of other enhancer-binding proteins.

LEF-1 is one member of a family of four proteins referred to as LEF/TCF transcription factors (LEF-1, TCF-1, TCF-3 and TCF-4). These factors play a crucial role in WNT/Wingless signaling, a signal transduction cascade that directs cell differentiation. Aberrant activation of the WNT/Wingless pathway is also a root cause in the genesis of certain cancers such as colon cancer, melanoma and breast cancer.

The LEF-1 protein is a 399 amino acid protein that appears as a cluster of polypeptides ranging in size between 55-57 kDa on SDS-PAGE analysis. Alternate splice forms of LEF-1 and other LEF/TCF family members have been identified, but the expression pattern and relative abundance of these alternate splice forms have not been well studied. They can appear on western blots as smaller immunoreactive forms.

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