The unique disulfide bond-stabilized W1 β4-β1 loop in the α4 β-propeller domain regulates integrin α4β7 affinity and signaling.

ABSTRACT: Integrin α4β7 mediates rolling and firm adhesion of lymphocytes pre- and post-activation, which is distinct from most integrins only mediating firm cell adhesion upon activation. This two-phase cell adhesion suggests a unique molecular basis for the dynamic interaction of α4β7 with its ligand, mucosal addressin cell adhesion molecule 1 (MAdCAM-1). Here we report that a disulfide bond-stabilized W1 β4-β1 loop in α4 β-propeller domain plays critical roles in regulating integrin α4β7 affinity and signaling. Either breaking the disulfide bond or deleting the disulfide bond-occluded segment in the W1 β4-β1 loop inhibited rolling cell adhesion supported by the low-affinity interaction between MAdCAM-1 and inactive α4β7 but negligibly affected firm cell adhesion supported by the high-affinity int

SUBMITTER: Yue J 

PROVIDER: S-EPMC3656279 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature