SP3 (E6Q9Q) Rabbit mAb #92190

SP3 (Specificity protein 3, Transcription factor Sp3) is a member of the Specificity Protein/Krüppel-like Factor (SP/KLF) family of DNA-binding transcription factors, which play a variety of important roles in cell function and homeostasis (1). There are nine known SP transcription factors (SP1-9); each contains a C2H2 zinc finger domain responsible for high affinity binding to GC-rich motifs that enables the activation or repression of target gene expression (2). SP1-4 contain a functional transactivation (TAD) in their amino terminus, which is notably absent from SP5-9. Despite nearly ubiquitous expression of SP transcription factors across most normal cells and tissues, research studies have identified links between expression levels and disease. It was shown, for example, that combined overexpression of v-Myc and SP1/SP3 led to oncogenic transformation of fibroblasts (3). Increased levels of SP transcription factors have likewise been reported in various tumor cells (2), while SP1, SP3, and SP4 were all reported to bind the VEGFR promoter and increase VEGF receptor expression in pancreatic cancer cells (4). The latter observation suggests that SP transcription factors may promote tumor cell growth through multiple mechanisms, including enhancing tumor angiogenesis, providing a potential avenue to therapeutic intervention.