TY - JOUR

T1 - Mechanisms of PDZ domain scaffold assembly illuminated by use of supported cell membrane sheets

AU - Erlendsson, Simon

AU - Thorsen, Thor Seneca

AU - Vauquelin, Georges

AU - Ammendrup-Johnsen, Ina

AU - Wirth, Volker

AU - Martinez, Karen L.

AU - Teilum, Kaare

AU - Gether, Ulrik

AU - Madsen, Kenneth Lindegaard

PY - 2019

Y1 - 2019

N2 - PDZ domain scaffold proteins are molecular modules orchestrating cellular signalling in space and time. Here, we investigate assembly of PDZ scaffolds using supported cell membrane sheets, a unique experimental setup enabling direct access to the intracellular face of the cell membrane. Our data demonstrate how multivalent protein-protein and protein-lipid interactions provide critical avidity for the strong binding between the PDZ domain scaffold proteins, PICK1 and PSD-95, and their cognate transmembrane binding partners. The kinetics of the binding were remarkably slow and binding strength two-three orders of magnitude higher than the intrinsic affinity for the isolated PDZ interaction. Interestingly, discrete changes in the intrinsic PICK1 PDZ affinity did not affect overall binding strength but instead revealed dual scaffold modes for PICK1. Our data supported by simulations suggest that intrinsic PDZ domain affinities are finely tuned and encode specific cellular responses, enabling multiplexed cellular functions of PDZ scaffolds.

AB - PDZ domain scaffold proteins are molecular modules orchestrating cellular signalling in space and time. Here, we investigate assembly of PDZ scaffolds using supported cell membrane sheets, a unique experimental setup enabling direct access to the intracellular face of the cell membrane. Our data demonstrate how multivalent protein-protein and protein-lipid interactions provide critical avidity for the strong binding between the PDZ domain scaffold proteins, PICK1 and PSD-95, and their cognate transmembrane binding partners. The kinetics of the binding were remarkably slow and binding strength two-three orders of magnitude higher than the intrinsic affinity for the isolated PDZ interaction. Interestingly, discrete changes in the intrinsic PICK1 PDZ affinity did not affect overall binding strength but instead revealed dual scaffold modes for PICK1. Our data supported by simulations suggest that intrinsic PDZ domain affinities are finely tuned and encode specific cellular responses, enabling multiplexed cellular functions of PDZ scaffolds.

KW - biochemistry

KW - chemical biology

KW - none

KW - post synaptic density

KW - scaffold proteins

KW - synaptic structure

U2 - 10.7554/eLife.39180

DO - 10.7554/eLife.39180

M3 - Journal article

C2 - 30605082

AN - SCOPUS:85060388425

VL - 8

SP - 1

EP - 27

JO - eLife

JF - eLife

SN - 2050-084X

M1 - e39180

ER -