Trans-activation and DNA-binding properties of the transcription factor, Sox-18

Abstract
Sox-18 is a member of the Sox multi-gene family (Sry-related HMG-box gene). We have bacterially expressed this 378 amlno acid protein and demonstrated sequence-specific binding to the Sox DNA-binding motif AACAAAG. A distinct 95 amino acid activation domain was mapped in Sox-18 using GAL4-Sox-18 fusions (amino acids 160–225). Furthermore, Sox-18 was capable of trans-actlvatlng gene expression through the AACAAAG motif. Our results suggest that Sox-18 functions as a classical frans-activator of gene expression.