HMG-box transcription factor 1 (HBP1)

HMG-box transcription factor 1 (HBP1) is a transcription factor characterized by the presence of a DNA-binding HMG box domain and an ataxin homology (AXH) domain. It primarily functions as a transcriptional repressor, regulating multiple genes implicated in cell proliferation and cell cycle control, including direct repression or activation of targets such as CDKN2A (p16^INK4A^), CDKN1A (p21^CIP1^), and CCND1 (cyclin D1). HBP1 acts as a potent inhibitor of cell cycle progression, promotes cellular senescence, and modulates terminal differentiation in several cell lineages. It is involved in suppressing oncogenic signaling by inhibiting transcription factors like MYC and interfering with the WNT/β-catenin pathway. HBP1 has thus been identified as a tumor suppressor in several cancer types, though it may act as an oncogenic factor in some contexts (e.g., nasopharyngeal carcinoma). Its activity is regulated by post-translational modifications, including ubiquitination, phosphorylation, and acetylation, and its levels are modulated by microRNAs and signaling pathways such as PI3K/AKT. HBP1 is also implicated as a biomarker in osteoarthritis and shows reduced expression in various cancers relative to normal tissues[1][2][3][4].

Other names

HMG box-containing protein 1HBP1High mobility group box transcription factor 1high mobility group box transcription factor 1HMG box transcription factor 1

Transcriptional repression of target genes (such as MYC, LEF1, TCF4, cyclin D1), Inhibition of the WNT/β-catenin pathway, Chromatin remodeling via interaction with proteins such as HDACs, Sin3, and p300/CBP