Regulates protein folding in the endoplasmic reticulum (ER) lumen. Forms a complex in the ER with SDF2 and MED37A/BIP1 which is required for the proper accumulation and function of the surface-exposed leucine-rich repeat receptor kinases EFR involved in pathogen-associated molecular pattern (PAMP) triggered immunity. Interacts with SDF2 and MED37A/BIP1. Expressed in leaves, flower buds and flowers. By tunicamycin. N-glycosylated. No visible phenotype under normal growth conditions, but mutant plants are insensitive to seedling growth inhibition in response to the pathogen-associated molecular pattern (PAMP) elf18. The double mutant erdj3b and p58ipk is male gametophytic lethal.