Atypical Ras-like protein that acts as a potent regulator of NF-kappa-B activity by preventing the degradation of NF-kappa-B inhibitor beta (NFKBIB) by most signals, explaining why NFKBIB is more resistant to degradation. May act by blocking phosphorylation of NFKBIB and mediating cytoplasmic retention of p65/RELA NF-kappa-B subunit. It is unclear whether it acts as a GTPase. Both GTP- and GDP-bound forms block phosphorylation of NFKBIB (By similarity). Interacts with both NF-kappa-B inhibitor alpha (NFKBIA) and beta (NFKBIB) in vitro. However, it probably only interacts with NFKBIB in vivo. Forms a complex with NFKBIB and NF-kappa-B heterodimer (p50/NFKB1 and p65/RELA). Also interacts with c-Rel (REL) (By similarity). In contrast to other members of the Ras family, the members of the KappaB-Ras subfamily do not contain the conserved Gly and Gln residues in positions 13 and 65, which are replaced by Leu residues, and are therefore similar to the constitutively active forms of oncogenic forms of Ras. This suggests that members of this family are clearly different from other small GTPases proteins. Belongs to the small GTPase superfamily. Ras family. KappaB-Ras subfamily.