The most represented components of clathrin-coated vesicles (CCVs) are clathrin triskelia and the adaptors clathrin assembly lymphoid myeloid leukemia protein (CALM) and the heterotetrameric complex AP2. Investigation of the dynamics of AP180-amino-terminal-homology (ANTH) recruitment during CCV formation has been hampered by CALM toxicity upon overexpression. We used knock-in gene editing to express a C-terminal–attached fluorescent version of CALM, while preserving its endogenous expression levels, and cutting-edge live-cell microscopy approaches to study CALM recruitment at forming CCVs. Our results demonstrate that CALM promotes vesicle completion upon membrane tension increase as a function of the amount of this adaptor present. Since the expression of adaptors, including CALM, differs among cells, our data support a model in which the efficiency of clathrin-mediated endocytosis is tissue specific and explain why CALM is essential during embryogenesis and red blood cell development.

网格蛋白包被囊泡 (CCV) 中最具代表性的成分是网格蛋白 triskelia 和适配器网格蛋白组装淋巴样髓细胞白血病蛋白 (CALM) 和异四聚体复合物 AP2。对 CCV 形成过程中 AP180-氨基末端同源性 (ANTH) 募集动态的研究受到过表达时 CALM 毒性的阻碍。我们使用敲入基因编辑来表达 CALM 的 C 端附加荧光版本，同时保留其内源性表达水平，并使用尖端的活细胞显微镜方法来研究 CALM 在形成 CCV 时的募集。我们的结果表明 CALM 在膜张力增加时促进囊泡完成，这是该适配器存在量的函数。由于包括 CALM 在内的适配器的表达在细胞之间有所不同，