Chloride intracellular channel protein 4 (CLIC4) exists in both soluble and 
membrane-associated forms, and is implicated in diverse cellular processes, 
ranging from ion channel formation to intracellular membrane remodeling. CLIC4 
is rapidly recruited to the plasma membrane by lysophosphatidic acid (LPA) and 
serum, suggesting a possible role for CLIC4 in exocytic-endocytic trafficking. 
However, the function and subcellular target(s) of CLIC4 remain elusive. Here, 
we show that in HeLa and MDA-MB-231 cells, CLIC4 knockdown decreases cell-matrix 
adhesion, cell spreading and integrin signaling, whereas it increases cell 
motility. LPA stimulates the recruitment of CLIC4 to β1 integrin at the plasma 
membrane and in Rab35-positive endosomes. CLIC4 is required for both the 
internalization and the serum- or LPA-induced recycling of β1 integrin, but not 
for EGF receptor trafficking. Furthermore, we show that CLIC4 suppresses Rab35 
activity and antagonizes Rab35-dependent regulation of β1 integrin trafficking. 
Our results define CLIC4 as a regulator of Rab35 activity and serum- and 
LPA-dependent integrin trafficking.