UBA-like domain found in nascent polypeptide-associated complex subunit alpha (NACA) and putative NACA-like protein (NACP1)
NACA, also called NAC-alpha or alpha-NAC, together with BTF3, also called Beta-NAC, form the nascent polypeptide-associated complex (NAC) which is a cytosolic protein chaperone that contacts the nascent polypeptide chains as they emerge from the ribosome. Besides, NACA has a high affinity for nucleic acids and exists as part of several protein complexes playing a role in proliferation, apoptosis, or degradation. It is a cytokine-modulated specific transcript in the human TF-1 erythroleukemic cell line. It also acts as a transcriptional co-activator in osteoblasts by binding to phosphorylated c-Jun, a member of the activator-protein-1 (AP-1) family. Moreover, NACA binds to and regulates the adaptor protein Fas-associated death domain (FADD). In addition, NACA functions as a novel factor participating in the positive regulation of human erythroid-cell differentiation. Both NACA and BTF3 harbor an NAC domain that mediates the dimerization of the two subunits. By contrast, NACA has an extra ubiquitin-associated (UBA) domain in the C-terminus. In addition to NACA, the family includes NACP1, also called Alpha-NAC pseudogene 1 or NAC-alpha pseudogene 1. The biological function of NACP1 remains unclear.
Jiyao W et al.(2023). "The conserved domain database in 2023.",