Inhibits the activity of dimeric NF-kappa-B/REL complexes by trapping REL dimers in the cytoplasm through masking of their nuclear localization signals. On cellular stimulation by immune and pro-inflammatory responses, becomes phosphorylated promoting ubiquitination and degradation, enabling the dimeric RELA to translocate to the nucleus and activate transcription. Interacts with RELA; the interaction requires the nuclear import signal. Interacts with NKIRAS1 and NKIRAS2. Part of a 70-90 kDa complex at least consisting of CHUK, IKBKB, NFKBIA, RELA, ELP1 and MAP3K14. Interacts with isoform 1 and isoform 2 of RWDD3; the interaction enhances sumoylation. Interacts (when phosphorylated at the 2 serine residues in the destruction motif D-S-G-X(2,3,4)-S) with BTRC. Associates with the SCF(BTRC) complex, composed of SKP1, CUL1 and BTRC; the association is mediated via interaction with BTRC. Part of a SCF(BTRC)-like complex lacking CUL1, which is associated with RELA; RELA interacts directly with NFKBIA. Interacts with PRMT2. Interacts with PRKACA in platelets; this interaction is disrupted by thrombin and collagen. Interacts with HIF1AN. Interacts with MEFV. Interacts with DDRGK1; positively regulates NFKBIA phosphorylation and degradation. (Microbial infection) Interacts with HBV protein X. Shuttles between the nucleus and the cytoplasm by a nuclear localization signal (NLS) and a CRM1-dependent nuclear export. Induced in adherent monocytes. Phosphorylated; disables inhibition of NF-kappa-B DNA-binding activity. Phosphorylation at positions 32 and 36 is prerequisite to recognition by UBE2D3 leading to polyubiquitination and subsequent degradation. Sumoylated; sumoylation requires the presence of the nuclear import signal. Sumoylation blocks ubiquitination and proteasome-mediated degradation of the protein thereby increasing the protein stability. Monoubiquitinated at Lys-21 and/or Lys-22 by UBE2D3. Ubiquitin chain elongation is then performed by CDC34 in cooperation with the SCF(FBXW11) E3 ligase complex, building ubiquitin chains from the UBE2D3-primed NFKBIA-linked ubiquitin. The resulting polyubiquitination leads to protein degradation. Also ubiquitinated by SCF(BTRC) following stimulus-dependent phosphorylation at Ser-32 and Ser-36. Deubiquitinated by porcine reproductive and respiratory syndrome virus Nsp2 protein, which thereby interferes with NFKBIA degradation and impairs subsequent NF-kappa-B activation. The disease is caused by variants affecting the gene represented in this entry. Belongs to the NF-kappa-B inhibitor family. NFKBIA mutation db