As a lipin family founding member, lipin1 exerts dual functions as a 
phosphatidate phosphatase enzyme and/or a co-transcriptional regulator in lipid 
metabolism. In fact, it is also involved in many other cell processes. In this 
study, we utilized pull down assay coupled with mass spectrometry (MS) to 
unravel protein-protein interaction networks of lipin1 in 293T human embryonic 
kidney cells. Pull-down assay on the Ni2+ -chelating column was used to isolate 
lipin1 complexes from 293T cells transfected with 6-His tagged lipin1. The 
lipin1 complexes were analyzed on Q Exactive mass spectrometer. A total of 30 
proteins were identified from label free quantitation of the MS data by Proteome 
Discoverer platform. The physical interaction between lipin1 and eEF1A1 was 
further affirmed in 293T cells transfected with 6-His tagged lipin1 and 
hepatocyte SMMC7721 cells by protein immunoprecipitation and immunofluorescence 
microscopy. Lipin1 also interacted with HIST1H2BK, which was confirmed in 
SMMC7721 cells by protein immunoprecipitation. Our proteomic analysis implicated 
lipin1 in novel roles in various cellular processes. © 2018 IUBMB Life, 
70(8):753-762, 2018.