GRASP depletion–mediated Golgi destruction decreases cell adhesion and migration via the reduction of a5ß1 integrin

Ahat, Erpan; Xiang, Yi; Zhang, Xiaoyan; Bekier, Michael E.; Wang, Yanzhuang

So far, we have confirmed that GRASP depletion reduces α5β1integrin level ( Figure 5 ) and decreases cell attachment and migration (Figures 1-4) . Reexpression of GRASP in the related GRASP-KO cells not only restored the α5β1-integrin level ( Figure 3C ) but also the defects in cell attachment (Figure 1 , G and H, and Supplemental Figure 1 ) and migration (Figures 3 and 4 and Supplemental Figures 1 and 3) . To determine whether the reduction of α5β1 integrin is the main reason for the decreased cell attachment and migration in GRASP-depleted cells, we exogenously expressed α5 integrin-GFP, which is known to restore the protein level of both α5 and β1 integrins (Isaji et al., 2006 (Isaji et al., , 2009 . As expected, expression of α5-GFP, but not GFP alone, increased the protein levels of both α5 and β1 integrins in GRASP single-and double-knockout cells to levels comparable to those of WT cells ( Figure 5H ). Significantly, Results are presented as mean ± SEM; statistical analysis was performed by comparison with WT cells (ctrl) using Student's t test. *, p < 0.05; **, p < 0.01; ***, p < 0.001. restoration of α5β1-integrin level in GRASP-KO cells largely rescued the reduced cell adhesion ( Figure 5I ) and migration (Supplemental Figure 5) phenotype. These results demonstrate that GRASP depletion decreases cell adhesion and migration via the reduction of α5β1 integrin.