Brain and muscle ARNT-like protein 1-Circadian locomotor output cycles protein kaput transcriptional complex (BMAL1-CLOCK) (BMAL1-CLOCK)

The Brain and muscle ARNT-like protein 1-Circadian locomotor output cycles protein kaput (BMAL1-CLOCK) transcriptional complex is the central molecular oscillator of the mammalian circadian clock (UniProt P49759, O00327). This heterodimeric complex, belonging to the basic helix-loop-helix-PAS (bHLH-PAS) family, binds to E-box motifs (5'-CACGTG-3') in the promoter regions of clock-controlled genes to drive their rhythmic expression (PubMed: 29444473). It initiates the transcription of its own repressors, the Period (PER) and Cryptochrome (CRY) proteins, creating a negative feedback loop that generates ~24-hour oscillations (PubMed: 30639518). Beyond timekeeping, the complex regulates vital physiological processes including glucose metabolism, lipid homeostasis, and cell cycle progression, making it a critical link between the biological clock and systemic health (PubMed: 28806104). Dysregulation of the BMAL1-CLOCK complex is implicated in metabolic syndrome, type 2 diabetes, cardiovascular diseases, and various cancers where circadian rhythmicity is often lost (PubMed: 33053377). Pharmacological modulation of the complex, either through direct inhibitors like CLK-821 or indirect modulators of its feedback loops (e.g., Rev-Erb or CRY ligands), represents a promising therapeutic avenue for treating circadian misalignment and metabolic disorders (PubChem: CID 56839146).

Other names

ARNTL-CLOCK complexMOP3-CLOCK complexBMAL1-CLOCK heterodimerMember of PAS protein 3-CLOCK complexBMAL1-CLOCK transcriptional complex

Modulation of E-box-mediated gene transcription, stabilization of cryptochrome-mediated inhibition, and activation of retinoic acid receptor-related orphan receptor (ROR) pathways.