U-box domain, a modified RING finger, found in erythroblast macrophage protein (Emp) and similar proteins
Emp, also known as cell proliferation-inducing gene 5 protein or macrophage erythroblast attacher (MAEA), is a key protein which functions in normal differentiation of erythroid cells and macrophages. It is a potential biomarker for hematopoietic evaluation of Hematopoietic stem cell transplantation (HSCT) patients. Emp was initially identified as a heparin-binding protein involved in the association of erythroblasts with macrophages. It promotes erythroid proliferation and maturation. It also plays an important role in erythroblastic island formation. Absence of Emp leads to failure of erythroblast nuclear extrusion. It is required in definitive erythropoiesis and plays a cell intrinsic role in the erythroid lineage. Emp contains a Lissencephaly type-1-like homology (LisH) motif, a C-terminal to LisH (CTLH) domain, and a RING-like U-box domain at the C-terminus.
Jiyao W et al.(2023). "The conserved domain database in 2023.",