Sorting of transmembrane proteins and their ligands at various compartments of the endocytic and secretory pathways is mediated by selective incorporation into clathrin-coated intermediates. Previous morphological and biochemical studies have shown that these clathrin-coated intermediates consist of spherical vesicles with a diameter of 60-100 nm. Herein, we report the use of fluorescent imaging of live cells to demonstrate the existence of a different type of transport intermediate containing associated clathrin coats. Clathrin and the adaptors GGA1 and adaptor protein-1, labeled with different spectral variants of the green fluorescent protein, are shown to colocalize to the trans-Golgi network and to a population of vesicles and tubules budding from it. These intermediates are highly pleiomorphic and move toward the peripheral cytoplasm for distanced of up to 10 mum with average speeds of -1 mum/s. The labeled clathrin and GGA1 cycle on and off membranes with half-times of 10-20 s, independently of vesicle budding. Our observations indicate the existence of a novel type of trans-Golgi network-derived carriers containing associated clathrin, GGA1 and adaptor protein-1 that are larger than conventional clathrin-coated vesicles, and that undergo long-range translocation in the cytoplasm before losing their coats.
机构:
Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USAUniv Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Brodsky, FM
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Chen, CY
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机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Chen, CY
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Knuehl, C
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机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Knuehl, C
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Towler, MC
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机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Towler, MC
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Wakeham, DE
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机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Costaguta, G
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Stefan, CJ
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机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Stefan, CJ
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Bensen, ES
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机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Bensen, ES
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Emr, SD
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机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Emr, SD
;
Payne, GS
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h-index: 0
机构:
Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
机构:
Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USAUniv Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Brodsky, FM
;
Chen, CY
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Chen, CY
;
Knuehl, C
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Knuehl, C
;
Towler, MC
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
Towler, MC
;
Wakeham, DE
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif San Francisco, Dept Biopharmaceut Sci, San Francisco, CA 94143 USA
机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Costaguta, G
;
Stefan, CJ
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Stefan, CJ
;
Bensen, ES
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Bensen, ES
;
Emr, SD
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA
Emr, SD
;
Payne, GS
论文数: 0引用数: 0
h-index: 0
机构:
Univ Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA