The auxilin-like phosphoprotein Swa2p is required for clathrin function in yeast
| Autor: | Douglas M. Cyr, Chih Ying Chen, Megan A. Higginbotham, Michael F. Ingram, Todd R. Graham, Walter E. Gall |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Endosome Recombinant Fusion Proteins Amino Acid Motifs Molecular Sequence Data Vesicular Transport Proteins Golgi Apparatus Saccharomyces cerevisiae Auxilin Biology Cell Fractionation Clathrin coat Clathrin General Biochemistry Genetics and Molecular Biology 03 medical and health sciences Transformation Genetic 0302 clinical medicine Animals HSP70 Heat-Shock Proteins Amino Acid Sequence 030304 developmental biology 0303 health sciences Agricultural and Biological Sciences(all) Biochemistry Genetics and Molecular Biology(all) Vesicle Cell Membrane Phosphoproteins Endocytosis Protein Structure Tertiary Transport protein Cell biology Protein Transport Tetratricopeptide Biochemistry Vacuoles biology.protein Clathrin adaptor proteins Carrier Proteins General Agricultural and Biological Sciences Sequence Alignment 030217 neurology & neurosurgery Protein Binding |
| Zdroj: | Current Biology. 10:1349-1358 |
| ISSN: | 0960-9822 |
| DOI: | 10.1016/s0960-9822(00)00771-5 |
| Popis: | Background: In eukaryotic cells, clathrin-coated vesicles transport specific cargo from the plasma membrane and trans -Golgi network to the endosomal system. Removal of the clathrin coat in vitro requires the uncoating ATPase Hsc70 and its DnaJ cofactor auxilin. To date, a requirement for auxilin and Hsc70 in clathrin function in vivo has not been demonstrated. Results: The Saccharomyces cerevisiae SWA2 gene, previously identified in a synthetic lethal screen with arf1 , was cloned and found to encode a protein with a carboxy-terminal DnaJ domain which is homologous to that of auxilin. Like auxilin, Swa2p has a clathrin-binding domain and is able to stimulate the ATPase activity of Hsc70. The swa2-1 allele recovered from the original screen carries a point mutation in its tetratricopeptide repeat (TPR) domain, a motif not found in auxilin but known in other proteins to mediate interaction with heat-shock proteins. Swa2p fractionates in the cytosol and appears to be heavily phosphorylated. Disruption of SWA2 causes slow growth and several phenotypes that are very similar to those exhibited by clathrin mutants. Furthermore, the swa2Δ mutant exhibits a significant increase in membrane- associated or -assembled clathrin relative to a wild-type strain. Conclusions: These results indicate that Swa2p is a clathrin-binding protein required for normal clathrin function in vivo . They suggest that Swa2p is the yeast ortholog of auxilin and has a role in disassembling clathrin, not only in uncoating clathrin-coated vesicles but perhaps in preventing unproductive clathrin assembly in vivo . |
| Databáze: | OpenAIRE |
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