Fig. 6: Allosteric regulation of SAM123-mediated interactions.
From: Structural basis of liprin-α-promoted LAR-RPTP clustering for modulation of phosphatase activity
a Analysis of the different target-binding surfaces on liprin-α_SAM123. The three liprin-α complex structures are presented with liprin-α_SAM123 in the same orientation. b, c Analytical gel filtration analysis showing the binding of liprin-α2_SAM123 to LAR with or without liprin-β1 (b) and to liprin-β1 (c). d SDS-PAGE analysis of the collected gel filtration fractions of the α2_SAM123/LAR_D1D2/β1-α_SAM123 mixture and the α2_SAM123/β1-α_SAM123 mixture as shown in (b) and (c), respectively. e Structural comparison of the LAR-bound SAM1 and liprin-β1-bound SAM1. Residues with large conformational or positional changes were shown in stick model. The steric crash between E882 in the LAR-bound SAM1 and L820 in liprin-β1, the critical liprin-α-binding site, was highlighted by a red circle. f, g Cell imaging analysis of cellular localization of liprin-β1. Endogenous liprin-α1 and liprin-β1 co-localized in the peripheral regions of the focal adhesion (FA), marked by GFP-paxillin (f). The localization of endogenous liprin-β1 was further analyzed in cells transfected with wild-type LAR-Flag (g) and its F1829E mutant (h). Scale bar, 10 μm. Regions of interesting were highlighted and enlarged as insets. Results were further confirmed by line profile analysis shown on the right.
