title: Microtubule-dependent endosomal sorting of clathrin-independent cargo by Hook1.
abstract: Many plasma membrane (PM) proteins enter cells nonselectively through clathrin-independent endocytosis (CIE). Here, we present evidence that cytoplasmic sequences in three CIE cargo proteins-CD44, CD98, and CD147-were responsible for the rapid sorting of these proteins into endosomal tubules away from endosomes associated with early endosomal antigen 1 (EEA1). We found that Hook1, a microtubule- and cargo-tethering protein, recognized the cytoplasmic tail of CD147 to help sort it and CD98 into Rab22a-dependent tubules associated with recycling. Depletion of Hook1 from cells altered trafficking of CD44, CD98, and CD147 toward EEA1 compartments and impaired the recycling of CD98 back to the PM. In contrast, another CIE cargo protein, major histocompatibility complex class I, which normally traffics to EEA1 compartments, was not affected by depletion of Hook1. Loss of Hook1 also led to an inhibition of cell spreading, implicating a role for Hook1 sorting of specific CIE cargo proteins away from bulk membrane and back to the PM.
authors.affiliation: Laboratory of Cell Biology, Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Lymarie
authors.initials: L
authors.lastname: Maldonado-Báez
authors.forename: Nelson B
authors.initials: NB
authors.lastname: Cole
authors.forename: Helmut
authors.initials: H
authors.lastname: Krämer
authors.forename: Julie G
authors.initials: JG
authors.lastname: Donaldson
mesh_terms: D000595:Amino Acid Sequence; D051926:Basigin / Q000737:chemistry / Q000378:metabolism; D002451:Cell Compartmentation; D002465:Cell Movement; D002966:Clathrin / Q000378:metabolism*; D017124:Conserved Sequence; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D027261:Fusion Regulatory Protein-1 / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D033921:Vesicular Transport Proteins / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism
chemical_list: D002966:Clathrin; D027261:Fusion Regulatory Protein-1; D018960:Hyaluronan Receptors; D008869:Microtubule-Associated Proteins; D050505:Mutant Proteins; C484191:RAB22A protein, human; D033921:Vesicular Transport Proteins; C093846:early endosome antigen 1; C471055:hook1 protein, human; D051926:Basigin; D020691:rab GTP-Binding Proteins