Stromal antigen 1 (STAG1) (SA1)

Stromal antigen 1 (STAG1) encodes a nuclear protein and core subunit of the cohesin complex, a multisubunit structure (together with SMC1, SMC3, and RAD21) that ensures proper sister chromatid cohesion from DNA replication through mitosis. STAG1 is indispensable for genome organization, participating in chromatin looping, gene regulation, and telomere stability. It physically interacts with regulatory proteins like CTCF to demarcate chromatin domains and supports the structural architecture necessary for accurate chromosome segregation and transcriptional control. Pathogenic variants in STAG1 are associated with a spectrum of developmental disorders termed cohesinopathies, marked by intellectual disability, growth delays, and congenital anomalies. Somatic STAG1 loss in cancer (particularly when STAG2 is mutated) creates vulnerabilities that can be exploited therapeutically through synthetic lethality. Although no approved drugs directly target STAG1, it remains a significant research focus in developmental biology and cancer therapeutics.

Other names

SA1SCC3AMRD47STAG1_HUMAN

Synthetic lethality: Inhibition of STAG1 can induce cell death in STAG2-deficient tumor cells by exacerbating sister chromatid cohesion defects, leading to mitotic failure