Yeast epsins contain an essential N-terminal ENTH domain, bind clathrin and are required for endocytosis.
The mammalian protein epsin is required for endocytosis. In this study, we have characterized two homologous yeast proteins, Ent1p and Ent2p, which are similar to mammalian epsin. An essential function for the highly conserved N-terminal epsin N-terminal homology (ENTH) domain was revealed using deletions and randomly generated temperature-sensitive ent1 alleles. Changes in conserved ENTH domain residues in ent1(ts) cells revealed defects in endocytosis and actin cytoskeleton structure. The Ent1 protein was localized to peripheral and internal punctate structures, and biochemical fractionation studies found the protein associated with a large, Triton X-100-insoluble pellet. Finally, an Ent1p clathrin-binding domain was mapped to the final eight amino acids (RGYTLIDL*) in the Ent1 protein sequence. Based on these and other data, we propose that the yeast epsin-like proteins are essential components of an endocytic complex that may act at multiple stages in the endocytic pathway.
Wendland
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B
Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA. bwendland@jhu.edu
Steece
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KE
Emr
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D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002966:Clathrin / Q000378:metabolism*; D003599:Cytoskeleton; D004705:Endocytosis / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins
D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D002966:Clathrin; C121319:ENT1 protein, S cerevisiae; C121321:ENT2 protein, S cerevisiae; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins