Development of a method for quantitative analysis of in vivo interactions of pluripotency transcription factors Sox2, Oct4, Nanog by mass spectrometry
Ontology highlight
ABSTRACT: Protein-protein proximity of core pluripotency transcription factors plays an important role during cell reprogramming. Pluripotent embryonic stem (ES) cell identity is controlled by a trio of transcription factors: Sox2, Oct4, and Nanog. These proteins often bind to closely localized genomic sites. The precise mode by which Sox2, Oct4, and Nanog interact with DNA is likely to make a crucial contribution to their function. Here, a detailed protocol for in vivo detection and quantitative analysis of protein-protein proximity of Sox2 and Oct4 using Proximity Utilizing Biotinylation (PUB) method based on the use of the BAP/BirA (target/enzyme) system is described. The method includes design and cloning of DNA plasmid construct, transient transfection of HEK293T cells, Western blot analysis of nuclei fraction and LC-MS/MS analysis. Experiments with coexpression of BAP-X+BirA-Y (X, Y=Sox2, Oct4 and GFP as control) revealed strong biotinylation level of target proteins when X and Y were pluripotency transcription factors compared with control when X=GFP. Since mass spectrometry provides both high sensitivity and more accurate quantification of data a modified workflow was used, in which SDS-PAGE step was eliminated and His-tagged BAP-fused proteins from cell lysate were purified in 6M guanidine HCl buffer, washed, propionylated, digested directly on the Ni sepharose beads using trypsin and analysed on Q-TOF Impact II instrument. Using mass spectrometry allows making quantitative estimation of in vivo interaction of BAP-Sox2 and BirA-Oct4 which was demonstrated by measuring ratios of biotinylation levels of BAP fused either with Sox2 or GFP at different biotin pulse times. After vector preparation this protocol can be completed in seven working days.
INSTRUMENT(S): maXis
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Cell Culture, Early Embryonic Cell
DISEASE(S): Disease Free
SUBMITTER: Arman Kulyyassov
LAB HEAD: Arman Kulyyassov
PROVIDER: PXD015756 | Pride | 2020-01-21
REPOSITORIES: Pride
ACCESS DATA