The Effect Of Mimic Phosphorvlation Modification Of Bcl-2 On The Interaction Between Bcl-2 And Nur77

Bcl-2 mainly executes anti-apoptotic function in the Bcl-2 family.Nuclear orphan receptor Nur77 can be translocated from the nucleus to the mitochondria.It interacts with Bcl-2 to reverse the function of Bcl-2 from a protector to a cell killer,thereby inducing cell apoptosis.The function of Bcl-2 is regulated by post-translational modification,such as the phosphorylation of T69 and S70 in the intrinsically disordered loop between BH3 and BH4 motifs.Its significance remains controversial.Due to the poor solubility of the membrane protein Bcl-2 in solution,the present structural studies are based on the chimera Bcl-2/xl,ignoring the regulation of phosphorylation modifications on the loop region and lacking the relevant structural information of the full-length Bcl-2 protein.At present,the effect of phosphorylation modification of T69 and S70 in the loop region on the interaction of the two proteins is still unclear,and there is a lack of related researches at the atomic level.Therefore,we truncated the entire transmembrane region and constructed a full-length intracellular Bcl-2 containing loop region(1-218 of Bcl-2),a GST-Loop containing only Loop region(35?91 of Bcl-2),a chimera Bcl-2/xl(1?34 of Bcl-2,35?50 of Bcl-xl,92?207 of Bcl-2)and two full-length mutants containing T69E and S70E to mimic the stabilized phosphorylation modification,and investigated the interactions by combining CD,Western Blot and NMR methods.We find that the full-length Bcl-2 has a stronger interaction with Nur77 compared to the Bcl-2/xl chimera and GST-Loop,and the phosphorylation modification mimicked by T69E significantly weakens the interaction between Bcl-2 and Nur77.These results will provide essensial information on the future researches based on Bcl-2 and Nur77 signal transduction pathways and the apoptosis targeting cancer cells.