Shared as well as distinct roles of EHD proteins revealed by biochemical and functional comparisons in mammalian cells and C. elegans
| Autor: | Guo Guang Ying, Aharon Solomon, Mark A. Rainey, Vimla Band, Qingshen Gao, Pankit Parikh, Manju George, Hamid Band |
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| Rok vydání: | 2007 |
| Předmět: |
Male
Protein family Mutant Endocytic recycling Plasma protein binding Cell Line Mice 03 medical and health sciences 0302 clinical medicine Protein-fragment complementation assay Animals Humans RNA Small Interfering lcsh:QH573-671 Caenorhabditis elegans Caenorhabditis elegans Proteins 030304 developmental biology 0303 health sciences biology lcsh:Cytology Transferrin RNA Cell Biology biology.organism_classification Endocytosis Cell biology Transport protein Protein Transport Phenotype rab GTP-Binding Proteins Female Carrier Proteins 030217 neurology & neurosurgery Protein Binding Research Article |
| Zdroj: | BMC Cell Biology, Vol 8, Iss 1, p 3 (2007) BMC Cell Biology |
| ISSN: | 1471-2121 |
| DOI: | 10.1186/1471-2121-8-3 |
| Popis: | Background The four highly homologous human EHD proteins (EHD1-4) form a distinct subfamily of the Eps15 homology domain-containing protein family and are thought to regulate endocytic recycling. Certain members of this family have been studied in different cellular contexts; however, a lack of concurrent analyses of all four proteins has impeded an appreciation of their redundant versus distinct functions. Results Here, we analyzed the four EHD proteins both in mammalian cells and in a cross-species complementation assay using a C. elegans mutant lacking the EHD ortholog RME-1. We show that all human EHD proteins rescue the vacuolated intestinal phenotype of C. elegans rme-1 mutant, are simultaneously expressed in a panel of mammalian cell lines and tissues tested, and variably homo- and hetero-oligomerize and colocalize with each other and Rab11, a recycling endosome marker. Small interfering RNA (siRNA) knock-down of EHD1, 2 and 4, and expression of dominant-negative EH domain deletion mutants showed that loss of EHD1 and 3 (and to a lesser extent EHD4) but not EHD2 function retarded transferrin exit from the endocytic recycling compartment. EH domain deletion mutants of EHD1 and 3 but not 2 or 4, induced a striking perinuclear clustering of co-transfected Rab11. Knock-down analyses indicated that EHD1 and 2 regulate the exit of cargo from the recycling endosome while EHD4, similar to that reported for EHD3 (Naslavsky et al. (2006) Mol. Biol. Cell 17, 163), regulates transport from the early endosome to the recycling endosome. Conclusion Altogether, our studies suggest that concurrently expressed human EHD proteins perform shared as well as discrete functions in the endocytic recycling pathway and lay a foundation for future studies to identify and characterize the molecular pathways involved. |
| Databáze: | OpenAIRE |
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