A tubular EHD1-containing compartment involved in the recycling of major histocompatibility complex class I molecules to the plasma membrane.
The Eps15 homology (EH) domain-containing protein, EHD1, has recently been ascribed a role in the recycling of receptors internalized by clathrin-mediated endocytosis. A subset of plasma membrane proteins can undergo internalization by a clathrin-independent pathway regulated by the small GTP-binding protein ADP-ribosylation factor 6 (Arf6). Here, we report that endogenous EHD proteins, as well as transgenic tagged EHD1, are associated with long, membrane-bound tubules containing Arf6. EHD1 appears to induce tubule formation, which requires nucleotide cycling on Arf6 and intact microtubules. Mutations in the N-terminal P-loop domain or deletion of the C-terminal EH domain of EHD1 prevent association of EHD1 with tubules or induction of tubule formation. The EHD1 tubules contain internalized major histocompatibility complex class I (MHC-I) molecules that normally traffic through the Arf6 pathway. Recycling assays show that overexpression of EHD1 enhances MHC-I recycling. These observations suggest an additional function of EHD1 as a tubule-inducing factor in the Arf6 pathway for recycling of plasma membrane proteins internalized by clathrin-independent endocytosis.
Caplan
Steve
S
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Naslavsky
Naava
N
Hartnell
Lisa M
LM
Lodge
Robert
R
Polishchuk
Roman S
RS
Donaldson
Julie G
JG
Bonifacino
Juan S
JS
D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005805:Genes, MHC Class I; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D008285:Major Histocompatibility Complex; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014162:Transfection; D033921:Vesicular Transport Proteins
D000089982:ADP-Ribosylation Factor 6; D002352:Carrier Proteins; C120700:EHD1 protein, human; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human