Max-interacting protein 1 (MXI1) (MXI1)

Max-interacting protein 1 (MXI1) is a member of the basic helix-loop-helix leucine zipper (bHLHZ) family of transcription factors and serves as a critical antagonist to the MYC proto-oncogene [1][2]. It functions by forming heterodimers with MAX, thereby competing with MYC for available MAX proteins and binding to E-box DNA sequences to repress transcription rather than activate it [1][3]. This repression is often mediated through the recruitment of the Sin3 corepressor complex and histone deacetylases [3]. Due to its role in counteracting MYC-driven cellular proliferation and transformation, MXI1 is generally characterized as a tumor suppressor, and its downregulation or loss is associated with various malignancies, including prostate and lung cancers [4][5]. While direct pharmacological targeting of MXI1 remains a challenge in drug development, it is a focal point in strategies aimed at modulating the MYC/MAX/MAD network to treat MYC-dependent cancers [6]. Furthermore, MXI1 is involved in regulating cell differentiation and maintaining genomic stability by balancing the proliferative signals of the MYC network [1][6].

Other names

MXI1MXIMAD2BHLHC11Basic helix-loop-helix family member c11Max-interacting protein

Competitive inhibition of MYC-MAX heterodimerization and recruitment of Sin3-HDAC corepressor complexes to E-box elements [1][3].