Objective Various highly conserved genes and proteins are expressed during embryonic development.Neuronal Development-Associated Protein (NDAP) is a newly identified protein which was cloned and identified by our laboratory using RNA arbitrary primed polymerase chain reaction (RAP-PCR).In our previous study, we demonstrated that NDAP was differentially expressed in primary culture of cerebral cortical neurons during development and regulated by neurotrophins.We transfected astrocytes with NDAP and found over-expressing NDAP would cause cellular apoptosis.Thus, differential expression of NDAP might play an important role in apoptosis regulation during development.Methods NDAP-EGFP was localized on the endoplasmic reticulum by over-expressing NDAP-EGFP in primary cultured astrocytes.NDAP polyclonal antibody was produced for further NDAP studies.Results (1) Endogenous NDAP was also localized on endoplasmic reticulum.(2) Over-expression of NDAP in primary cultured astrocytes, neurons and cell lines caused apoptosis.(3) Over-expression of NDAP could up-regulate many endoplasmic reticulum stress related molecules such as Bip, ATF4 and CHOP, which indicated that NDAP might induce endoplasmic reticulum stress through Bip-ATF4-CHOP pathway.Conclusion As an endoplasmic reticulum resident protein, up-regulation of NDAP may play an important role in endoplasmic reticulum-regulated apoptosis during development.