Functions as an activator of NF-kappa-B through increased phosphorylation of the IKK complex. May function in neuronal cells differentiation. May play a role in vesicular transport from endoplasmic reticulum to Golgi. Component of the multisubunit TRAPP (transport protein particle) complex, which includes at least TRAPPC2, TRAPPC2L, TRAPPC3, TRAPPC3L, TRAPPC4, TRAPPC5, TRAPPC8, TRAPPC9, TRAPPC10, TRAPPC11 and TRAPPC12 (By similarity). Directly interacts with IKBKB and MAP3K14. Processes and cell bodies of neurons. Expressed in neurons of the pyramidal layer of the cortex, in spinal cord motor neurons and white matter neurons (at protein level). Belongs to the NIBP family.