| Primary Identifier | IPR043563 | Type | Family |
| Short Name | Sp110/Sp140/Sp140L |
| description | This entry includes a group of nuclear dot-associated proteins, including Sp110/Sp140/Sp140L from humans. They are proteins with a constituent of nuclear domains, also known as nuclear dots (NDs). Sequences similar to the Sp100 homodimerization/ND-targeting region occur in several other proteins and constitute a novel protein motif, termed HSR domain (for homogeneously-staining region) [].Sp110 is a leukocyte-specific component of the nuclear body []. It may function as a nuclear hormone receptor transcriptional coactivator that may play a role in inducing differentiation of myeloid cells []. It is also involved in resisting intracellular pathogens and functions as an important drug target for preventing intracellular pathogen diseases, such as tuberculosis, hepatic veno-occlusive disease, and intracellular cancers [, ]. Sp110 gene polymorphisms may be associated with susceptibility to tuberculosis in Chinese population []. The function of nuclear protein Sp140 is not known, though it contains several chromatin related modules such as plant homeodomain (PHD), bromodomain (BRD) and SAND domain, which suggests a role in chromatin-mediated regulation of gene expression []. It also harbours a nuclear localisation signal and a dimerisation domain (HSR or CARD domain). The PHD finger of Sp140 presents an atypical fold which does not bind to histone H3 tails but binds to peptidylprolyl isomerase Pin1. Pin1 catalyses the isomerisation of a phospho-Threonine-Proline bond in Sp140-PHD and thus may modulate Sp140 function [].Human Sp140 is an interferon inducible nuclear leukocyte-specific protein that may be involved in the pathogenesis of acute promyelocytic leukemia and viral infection []. It localises to LYSP100-associated nuclear dots and is also a component of the promyelocytic leukemia nuclear body (PML-NBs) [, ]. The Sp140 locus has been identified as a lymphocytic leukemia (CLL) risk locus [].This family also includes protein Sp140-like (SP140L) []. |
