Activating transcription factor 4 (ATF4) is an osteoblast-enriched transcription factor that
regulates osteocalcin transcription and osteoblast terminal differentiation. To identify
functional partners of ATF4, we applied ROS17/2.8 osteoblast nuclear extracts and purified
recombinant His-ATF4 onto a Ni+ affinity matrix chromatography column. Vimentin was
identified by liquid chromatography-mass spectrometry. Coimmunoprecipitation and
pulldown assays revealed that vimentin interacted with ATF4 with its first leucine zipper …