The acidic intrinsically disordered region of the inflammatory mediator HMGB1 mediates fuzzy interactions with chemokine CXCL12

Data contain: The acidic intrinsically disordered region of the inflammatory mediator HMGB1 mediates fuzzy interactions with chemokine CXCL12 Data contain: Figure 2: data generating bar graphs displayed in b,c,f,g,jk Figure 3: data generating bar graphs displayed in c,d,f,g Figure 4: data generating bar graphs displayed in c-f Figure 5: ITC sequential pulses displayed in Figure 5a-c, normalized MST signals displayed in Figure d,e Figure 6: SV-AUC data displayed in a-c, MS-SV analysis displayed in f Figure 7:SAXS data displayed in a-d Figure 8:Quantification of PLA signals displayed in a-c Supplementary S3: data generating bar graphs displayed in b-k Supplementary Figure S4:data generating bar graphs displayed in b-d; normalized MST signals displayed in e Supplementary Figure S5: data generating bargprahs displayed in panel a,b;d,e;g,h Supplementary Figure S6: ITC sequential pulses displayed in c,d Supplementary Figure S7:SV-AUC data displayed in a-i, MS-SV analysis displayed in k. Supplementary Figure S8: SAXS data displayed in a,b Supplementary Figure S9: HMGB1 SAXS dilution series displayed in a-c Supplementary Figure S10: CXCL12 SAXS dilution series displayed in a-c Supplementary Figure S11 SAXS data and EOM analysis displayed in a and b Figure S12: SAXS concentration series of frHMGB1 titrated with CXCL12 a-b Figure S13: Supplementary Figure S12: Fits to SAXS data of the a) SASREF and b)FoXSDock model of frHMGB1-CXCL12 complex Figure S15: OLIGOMER analysis, panel a,b Figure S16: PLA analysis, panel b Figure S17: uncropped gel in panel a, FACS analysis pnale c Reporting summary: AB1 Cell line information Supplementary Table 1: contains the AUC analysis of CXCL12, frHMGB1 and frHMGB1•CXCL12 at pH 7.5, 20 mM TrisHCl, 50 mM NaCl Supplementary Table 2: contains the calculated values from AUC analysis of CXCL12, frHMGB1 and frHMGB1●CXCL12, pH 7.5, 20 mM TrisHCl,150 mM NaCl Supplementary Table 3: contains the calculated values from AUC analysis of CXCL12-LM, frHMGB1 and frHMGB1●CXCL12-LM, pH 7.5, 20 mM TrisHCl, 50 mM NaC

The acidic intrinsically disordered region of the inflammatory mediator HMGB1 mediates fuzzy interactions with CXCL12

Abstract Chemokine heterodimers activate or dampen their cognate receptors during inflammation. The CXCL12 chemokine forms with the fully reduced (fr) alarmin HMGB1 a physiologically relevant heterocomplex (frHMGB1•CXCL12) that synergically promotes the inflammatory response elicited by the G-protein coupled receptor CXCR4. The molecular details of complex formation were still elusive. Here we show by an integrated structural approach that frHMGB1•CXCL12 is a fuzzy heterocomplex. Unlike previous assumptions, frHMGB1 and CXCL12 form a dynamic equimolar assembly, with structured and unstructured frHMGB1 regions recognizing the CXCL12 dimerization surface. We uncover an unexpected role of the acidic intrinsically disordered region (IDR) of HMGB1 in heterocomplex formation and its binding to CXCR4 on the cell surface. Our work shows that the interaction of frHMGB1 with CXCL12 diverges from the classical rigid heterophilic chemokines dimerization. Simultaneous interference with multiple interactions within frHMGB1•CXCL12 might offer pharmacological strategies against inflammatory conditions