SP140 nuclear body protein (SP140)

SP140 nuclear body protein is a leukocyte-restricted, interferon-inducible chromatin ‘reader’ belonging to the SP100 family, localized to promyelocytic leukemia (PML) nuclear bodies in human cells. It contains functional domains such as SAND (DNA binding and protein–protein interactions), plant homeodomain (PHD, reads histone methylation), bromodomain (reads histone acetylation), and CARD (multimerization), and harbors an intrinsically disordered region (IDR) relevant for phase separation and nuclear compartmentalization. SP140 acts predominantly as a transcriptional repressor, maintaining immune cell identity by silencing lineage-inappropriate genes through selective occupancy of heterochromatin regions. Genetic and functional studies link SP140 polymorphisms and expression changes to a range of immune-mediated diseases, including Crohn’s disease, multiple sclerosis, and chronic lymphocytic leukemia. Emerging evidence suggests roles in viral infection and as a regulator of inflammatory and immune gene programs in macrophages and B cells. SP140 may interact with viral proteins during infection (e.g., HIV-1 Vif) and regulate antiviral defense mechanisms.

Other names

Nuclear body protein SP140LYSP100LYSP100-ALYSP100-BLymphoid-restricted homolog of Sp100Nuclear autoantigen Sp-140Speckled 140 kDaLymphoid-specific SP100 homologSP140

No drugs directly targeting SP140 described in the search results, so mechanisms are not established. Its role in diseases suggests therapeutic strategies may seek to modulate its chromatin reader or transcriptional repressor activities.