Requirements for both Rac1 and Cdc42 in membrane ruffling and phagocytosis in leukocytes.
Requirements for both Rac1 and Cdc42 in membrane ruffling and phagocytosis in leukocytes.
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DOI：
10.1084/jem.186.9.1487
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发表时间：
1997-11-03
期刊：
影响因子：
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通讯作者：
Greenberg S
中科院分区：
文献类型：
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作者：
Cox D;Chang P;Zhang Q;Reddy PG;Bokoch GM;Greenberg S
连接异源三聚体G蛋白和Fcγ受体与肌动蛋白基细胞骨架的特定途径知之甚少。为了测试在由白细胞中结构多样的受体介导的细胞骨架事件中对Rho家族成员的需要，我们在RAW 264.7细胞中转染全长人趋化肽受体，并检查响应于趋化肽甲酰基-甲硫氨酰基-亮氨酰基-苯丙氨酸（FMLP）、集落刺激因子-1（CSF-1）、IgG包被的颗粒、和佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）。Rac 1 N17、Cdc 42 N17或N-嵌合蛋白的差距结构域的表达抑制对FMLP和CSF-1的细胞骨架反应，并阻断吞噬作用。富F-肌动蛋白的“吞噬杯”的积累被Rac 1 N17或Cdc 42 N17的表达部分抑制。相比之下，PMA诱导的ruffling不受Rac 1 N17表达的抑制，但被Cdc 42 N17表达所阻断，这表明这些构建体的细胞骨架抑制是不重叠的。这些结果表明白细胞运动对Rho家族GTPases的需求不同，并表明Rac 1和Cdc 42都是Fcγ受体介导的吞噬作用和巨噬细胞中结构不同受体介导的膜皱褶所需的。
Specific pathways linking heterotrimeric G proteins and Fcγ receptors to the actin-based cytoskeleton are poorly understood. To test a requirement for Rho family members in cytoskeletal events mediated by structurally diverse receptors in leukocytes, we transfected the full-length human chemotactic peptide receptor in RAW 264.7 cells and examined cytoskeletal alterations in response to the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP), colony stimulating factor–1 (CSF-1), IgG-coated particles, and phorbol 12-myristate 13-acetate (PMA). Expression of Rac1 N17, Cdc42 N17, or the GAP domain of n-chimaerin inhibited cytoskeletal responses to FMLP and CSF-1, and blocked phagocytosis. Accumulation of F-actin– rich “phagocytic cups” was partially inhibited by expression of Rac1 N17 or Cdc42 N17. In contrast, PMA-induced ruffling was not inhibited by expression of Rac1 N17, but was blocked by expression of Cdc42 N17, indicating that cytoskeletal inhibition by these constructs was nonoverlapping. These results demonstrate differential requirements for Rho family GTPases in leukocyte motility, and indicate that both Rac1 and Cdc42 are required for Fcγ receptor– mediated phagocytosis and for membrane ruffling mediated by structurally distinct receptors in macrophages.