Chromosome segregation 1 like protein (CSE1L)

Chromosome segregation 1 like protein (CSE1L, also known as Exportin-2, CAS, or XPO2) is a nuclear transport receptor that mediates the re-export of importin-alpha from the nucleus to the cytoplasm after it has delivered NLS-cargo proteins across the nuclear pore complex. CSE1L plays a vital role in nuclear-cytoplasmic transport by binding importin-alpha in the nucleus and releasing it in the cytoplasm in a process regulated by RanGTP and its co-factors. Beyond its transport function, CSE1L indirectly regulates gene silencing via the nuclear import of chromatin-associated and gene-repressive proteins, and has a noted role in cell proliferation, apoptosis inhibition, and tumorigenesis. Overexpression of CSE1L is often linked with cancer progression, metastasis, and poor patient prognosis. While not yet directly targeted by approved drugs, CSE1L is of significant interest as a potential therapeutic target and biomarker in oncology[1][2][3].

Other names

Exportin-2CASXPO2Importin-alpha re-exporterCellular apoptosis susceptibility proteinChromosome segregation 1-like proteinCSE1Exp2BCR/ABL fusion protein (historical/informal; not commonly used in modern nomenclature)

Drugs targeting CSE1L (if developed) would likely modulate nuclear export/import of key cargo proteins, impacting signal transduction pathways (e.g., NF-κB/MAPK)[3]. Inhibition could impact tumor cell proliferation and promote apoptosis by trapping nuclear factors or blocking export of growth-promoting proteins[3].