CLASP proteins and cargo are recruited to the nascent clathrin-coated pit

CLASP proteins are recruited to nascent clathrin-coated pits (CCPs) through interactions with AP-2 and clathrin. Although in this pathway cargo recruitment is depicted as occuring after the recruitment of bulk AP-2 and clathrin, a number of studies suggest that they are largely recruited concomitantly (Liu et al, 2010; reviewed in McMahon and Boucrot, 2011). Concurrent interactions with sorting signals in cargo cytoplasmic tails and with clathrin and/or AP-2 ensure that CLASPs and cargo are incorporated into the emerging CCP (Schmid et al, 2006; Edeling et al, 2006; reviewed in Traub, 2009; Traub and Bonifacino, 2013; Kirchausen et al, 2014). In addition, incorporation of CLASPs and cargo may play a role in regulating the timing and dynamics of endocytosis (Loerke et al, 2009; Mettlen et al, 2009; Soohoo et al, 2013; Mettlen et al, 2010; Puthenveedu et al, 2005).

CLASP蛋白通过与其配体AP-2和网格蛋白的结合，被招募至新生的网格蛋白包被凹陷（CCPs）。尽管在该途径中，货物招募被描绘为在大量AP-2和网格蛋白招募之后发生，但众多研究表明，它们在很大程度上是同时被招募的（Liu等，2010；参见McMahon和Boucrot，2011年综述）。同时与货物胞浆尾部的分类信号以及与网格蛋白和/或AP-2的相互作用，确保CLASPs和货物被整合进正在形成的CCPs中（Schmid等，2006；Edeling等，2006；参见Traub，2009年综述；Traub和Bonifacino，2013年综述；Kirchausen等，2014年综述）。此外，CLASPs和货物的整合可能在调节内吞作用的时机和动态方面发挥重要作用（Loerke等，2009；Mettlen等，2009；Soohoo等，2013；Mettlen等，2010；Puthenveedu等，2005年）。