Myc-associated factor X (MAX)

Myc-associated factor X (MAX) is a ubiquitously expressed **transcription factor** belonging to the basic helix-loop-helix leucine zipper (bHLHLZ) protein family[1][2][3]. MAX acts as an obligate dimerization partner for several transcription factors, most notably the **oncogene MYC** and its antagonists (e.g., MAD and MNT), thereby controlling specificity and affinity for E-box DNA binding sequences. Through heterodimerization, MAX enables MYC-driven activation or repression of target genes involved in cell proliferation, differentiation, cell cycle, apoptosis, and metabolism[1][2][3][4]. MAX can form homodimers, resulting in transcriptional repression by outcompeting activator complexes for DNA binding. Alterations in MAX—including mutations, loss, or decreased expression—are associated with cancer across multiple tissue types, both as a driver (by enabling dysregulated MYC activity) and as a diagnostic or prognostic marker. While MAX is recognized as a potential therapeutic target, direct pharmacological modulators are not yet in clinical use, though agents disrupting MYC–MAX interaction are under investigation[3][4].

Other names

Protein maxBHLHD4bHLHd4bHLHd5bHLHd6bHLHd7bHLHd8Class D basic helix-loop-helix protein 4Myc-associated factor XPDMCSclass D basic helix-loop-helix protein 4

(For investigational agents): Disruption of MYC–MAX dimerization to repress MYC-driven transcription; (Theoretical): Modulation of E-box DNA binding by influencing dimer composition (MYC-MAX heterodimer or MAX-MAX homodimer)