Responsible for the ER body formation. Regulates the number and shape of the ER bodies and the accumulation of PYK10 in ER bodies, but is not involved in the expression of PYK10. Has no interaction with PYK10 and is not part of the PYK10 complex. Interacts directly or indirectly with MEB1 and MEB2. Located in ER bodies. Expressed in roots. Detected in shoot apex. Induced by NAI1. Contains a N-terminal NAI2 domain (472-772). Loss of ER bodies accumulation in all parts of the seedling and alteration of PYK10 localization. 'Nai' means 'nothing' in Japanese. Homologous proteins are found only in Brassicales plants (PubMed:18780803).