Department of Molecular Medicine, Max Planck Institute for Biochemistry, 82152 Martinsried, Germany.
Department of Dermatology, Mayo Clinic, Rochester, MN 55905, USA.
J Cell Sci. 2020 Sep 23;133(18):jcs243683. doi: 10.1242/jcs.243683.
Integrin function depends on the continuous internalization of integrins and their subsequent endosomal recycling to the plasma membrane to drive adhesion dynamics, cell migration and invasion. Here we assign a pivotal role for Rabgap1 (GAPCenA) in the recycling of endocytosed active β1 integrins to the plasma membrane. The phosphotyrosine-binding (PTB) domain of Rabgap1 binds to the membrane-proximal NPxY motif in the cytoplasmic domain of β1 integrin subunits on endosomes. Silencing Rabgap1 in mouse fibroblasts leads to the intracellular accumulation of active β1 integrins, alters focal adhesion formation, and decreases cell migration and cancer cell invasion. Functionally, Rabgap1 facilitates active β1 integrin recycling to the plasma membrane through attenuation of Rab11 activity. Taken together, our results identify Rabgap1 as an important factor for conformation-specific integrin trafficking and define the role of Rabgap1 in β1-integrin-mediated cell migration in mouse fibroblasts and breast cancer cells.
整合素的功能取决于整合素的持续内化及其随后的内体再循环到质膜,以驱动黏附动力学、细胞迁移和侵袭。在这里,我们将 Rabgap1(GAPCenA)在将内化的活性β1 整合素再循环到质膜中的作用确定为关键作用。Rabgap1 的磷酸酪氨酸结合(PTB)结构域与质膜近端 NPxY 基序结合在β1 整合素亚基的细胞质结构域上,位于内体中。在小鼠成纤维细胞中沉默 Rabgap1 会导致活性β1 整合素在细胞内积累,改变焦点黏附形成,并降低细胞迁移和癌细胞侵袭。从功能上讲,Rabgap1 通过衰减 Rab11 的活性促进活性β1 整合素的再循环到质膜。总之,我们的研究结果确定 Rabgap1 是构象特异性整合素运输的重要因素,并定义了 Rabgap1 在小鼠成纤维细胞和乳腺癌细胞中β1 整合素介导的细胞迁移中的作用。