Clathrin light chain directs endocytosis by influencing the binding of the yeast Hip1R homologue, Sla2, to F-actin.
Clathrin light chain directs endocytosis by influencing the binding of the yeast Hip1R homologue, Sla2, to F-actin.
复制标题
网格蛋白光链通过影响酵母HIP1R同源物SLA2与F-肌动蛋白的结合来指导内吞作用。
DOI：
10.1091/mbc.e11-07-0628
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发表时间：
2011-10
影响因子：
3.3
通讯作者：
Lemmon SK
中科院分区：
文献类型：
--
作者：
Boettner DR;Friesen H;Andrews B;Lemmon SK
网格蛋白轻链 (LC) N 末端区域与 ANTH/talin 样蛋白的 Sla2/Hip1/Hip1R 家族相互作用。体内证据表明，LC-Sla2 结合对于释放 Sla2 在内吞层中肌动蛋白的附着非常重要。失去这种调节可以抑制内吞过程中的主要肌动蛋白缺陷。网格蛋白轻链 (CLC) 在网格蛋白介导的内吞作用中的作用尚不完全清楚。先前的研究表明，CLC N 末端 (CLC-NT) 与膜/肌动蛋白结合因子的 Hip1/Hip1R/Sla2 家族结合，并且 CLC-NT 在酵母中的过度表达可抑制网格蛋白重链突变体的内吞缺陷。为了阐明这种抑制的机制基础，我们对网格蛋白 CLC-NT 缺失突变 (clc1-Δ19-76) 进行了合成基因阵列分析。 clc1-Δ19-76 抑制了三种晚期内吞因子中无效突变的内化缺陷：两性蛋白（rvs161 和 rvs167）和 verprolin (vrp1)。在肌动蛋白沉降测定中，CLC 与 Sla2 结合抑制了 Sla2 与 F-肌动蛋白的相互作用。此外，clc1-Δ19-76对rvs和vrp表型的抑制需要Sla2肌动蛋白结合talin-Hip1/R/Sla2肌动蛋白束缚C端同源结构域，这表明clc1-Δ19-76通过延长Sla2与肌动蛋白的结合来促进内化。我们提出 CLC 通过修剪网格蛋白晶格中的 Sla2-肌动蛋白附着来指导内吞进程，为膜内化提供方向。
The clathrin light-chain (LC) N-terminal region interacts with the Sla2/Hip1/Hip1R family of ANTH/talin–like proteins. In vivo evidence shows that LC–Sla2 binding is important for releasing Sla2 attachments to actin in the endocytic coat. Loss of this regulation can suppress major actin defects during endocytosis. The role of clathrin light chain (CLC) in clathrin-mediated endocytosis is not completely understood. Previous studies showed that the CLC N-terminus (CLC-NT) binds the Hip1/Hip1R/Sla2 family of membrane/actin–binding factors and that overexpression of the CLC-NT in yeast suppresses endocytic defects of clathrin heavy-chain mutants. To elucidate the mechanistic basis for this suppression, we performed synthetic genetic array analysis with a clathrin CLC-NT deletion mutation (clc1-Δ19-76). clc1-Δ19-76 suppressed the internalization defects of null mutations in three late endocytic factors: amphiphysins (rvs161 and rvs167) and verprolin (vrp1). In actin sedimentation assays, CLC binding to Sla2 inhibited Sla2 interaction with F-actin. Furthermore, clc1-Δ19-76 suppression of the rvs and vrp phenotypes required the Sla2 actin-binding talin-Hip1/R/Sla2 actin-tethering C-terminal homology domain, suggesting that clc1-Δ19-76 promotes internalization by prolonging actin engagement by Sla2. We propose that CLC directs endocytic progression by pruning the Sla2-actin attachments in the clathrin lattice, providing direction for membrane internalization.