Phosphorylation-regulated HMGA1a-P53 interaction unveils the function of HMGA1a acidic tail phosphorylations via synthetic proteins. Issue 5 (20th May 2021)

• Record Type: Journal Article
• Authors: Wei, Tongyao; Liu, Heng; Chu, Bizhu; Blasco, Pilar; Liu, Zheng; Tian, Ruijun; Li, David Xiang; Li, Xuechen
• Is Part Of: Cell chemical biology. Volume 28:Issue 5(2021)
• Page Start: 722
• Page End: 732.e8
• Publication Date: 2021-05-20
• Subjects: chemical protein synthesis -- intrinsically disordered protein -- protein phosphorylation -- HMGA -- P53 -- conformational change; Biochemistry -- Periodicals; 572.05
• DOI: 10.1016/j.chembiol.2021.01.007
• Languages: English
• ISSNs: 2451-9456

Abstract

Summary: As a typical member of intrinsically disordered proteins (IDPs), HMGA1a carries many post-translational modifications (PTMs). To study the undefined function of acidic tail phosphorylations, seven HMGA1a proteins with site-specific modification(s) were chemically synthesized via Ser/Thr ligation. We found that the phosphorylations significantly inhibit HMGA1a-P53 interaction and the phosphorylations can induce conformational change of HMGA1a from an "open state" to a "close state." Notably, the positively charged lysine-arginine (KR) clusters are responsible for modulating HMGA1a conformation via electrostatic interaction with the phosphorylated acidic tail. Finally, we used a synthetic protein-affinity purification mass spectrometry (SP-AP-MS) methodology to profile the specific interactors, which further supported the function of HMGA1a phosphorylation. Collectively, this study highlights a mechanism for regulating IDPs' conformation and function by phosphorylation of non-protein-binding domain and showcases that the protein chemical synthesis in combination with mass spectrometry can serve as an efficient tool to study the IDPs' PTMs. Graphical abstract: Highlights: HMGA1a proteins with site-specific PTMs were obtained by chemical synthesis HMGA1a-P53 interaction is inhibited by HMGA1a acidic tail phosphorylation Phosphorylation induces conformational change of HMGA1a The KR clusters-acidic tail interaction is critical for the conformation change Abstract : Generating homogeneous proteins with site-specific modifications is possible through chemical synthesis. Wei et al. demonstrated that an intrinsically disordered protein, HMGA1a, can experience a conformational change from an "open state" to a "close state" upon acidic tail phosphorylation, thus regulating the protein-protein interaction.