Transcription factor Sp3 (Sp3) (Sp3)

Transcription factor Sp3 (Sp3) is a member of the specificity protein/Krüppel-like factor (Sp/KLF) family that binds to GC-rich DNA sequences, known as GC boxes, in the promoters of various genes (Safe et al., 2014, PubMed: 24513305). It is ubiquitously expressed and functions as a versatile regulator of gene expression, acting as either a transcriptional activator or a repressor depending on the cellular context and post-translational modifications such as sumoylation (Sapetschnig et al., 2002, PubMed: 12145205). Sp3 plays a critical role in fundamental biological processes, including cell cycle progression, apoptosis, and differentiation (UniProt: Q02447). In many types of cancer, Sp3 is overexpressed and contributes to tumor growth and survival by upregulating genes involved in angiogenesis and cell proliferation (Safe and Abdelrahim, 2005, PubMed: 15905560). Therapeutic targeting of Sp3-mediated transcription often involves small molecules like Mithramycin A, which binds to GC-rich DNA to displace Sp proteins, or compounds like tolfenamic acid that induce Sp3 protein degradation (Safe et al., 2014, PubMed: 24513305). Because Sp3 regulates a wide array of essential genes, drugs targeting this factor often face challenges related to systemic toxicity and off-target effects.

Other names

Specificity protein 3SPR2GC-binding factor

Competitive inhibition of DNA binding at GC-rich promoter sequences or induction of proteasomal degradation of the Sp3 protein.