Ishido Miwako

The Scripps Research Institute, La Jolla, CA, United States

Are you Ishido Miwako?

Claim your profile

Publications (3)10.21 Total impact

  • Ishido Miwako, Sandra L Schmid
    [Show abstract] [Hide abstract]
    ABSTRACT: The low density lipoprotein receptor-related protein (LRP) binds multiple, distinct ligands and participates in constitutive endocytosis and signal transduction. Using an in vitro reconstitution system and a new biochemical complementation assay, we have explored the limiting cytosolic requirements for endocytosis of LRP from isolated plasma membranes. We find that clathrin, AP2 and dynamin do not support efficient LRP uptake and that additional factors present in a 30% ammonium sulfate supernatant fraction of bovine brain cytosol (AS supt) are required. Fractionation of the AS supt revealed that multiple and redundant factors are required to support LRP endocytosis. Among these, we identified Hsc70, synaptojanin1 and CRMP-2 by mass spectrometry. Our data suggest that LRP, which bears several distinct endocytic motifs in its cytoplasmic domain, may use multiple pathways for endocytosis in vitro.
    Experimental Cell Research 06/2006; 312(8):1335-44. · 3.56 Impact Factor
  • Ishido Miwako, Sandra L Schmid
    [Show abstract] [Hide abstract]
    ABSTRACT: Endocytic clathrin-coated vesicle (CCV) formation is a complex process involving a large number of proteins and lipids. The minimum machinery and the hierarchy of the events involved in CCV formation have yet to be defined. Here we describe an in vitro assay for CCV formation from highly purified rat liver plasma membranes. This rapid and easy assay can be used to quantitatively evaluate the different protein requirements for different endocytic receptors.
    Methods in Enzymology 02/2005; 404:503-11. · 2.00 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have developed a new rapid cell-free assay for endocytic clathrin-coated vesicle formation using highly purified rat liver plasma membrane sheets. After incubation in the presence of cytosol and nucleotides, released vesicles were collected by high-speed centrifugation and incorporated cargo receptors were detected by Western blotting. Three different cargo receptors were internalized into vesicles while a receptor, known to be excluded from coated pits, was not. The recruitment of cargo receptors into the vesicle fraction was cytosol, ATP and temperature-dependent and was enhanced by addition of GTP. Vesicle formation in this assay was confirmed by subcellular fractionation and EM analysis. Plasma membranes stripped of their endogenous coat proteins with 0.5 m Tris retained vesicle formation activity, which was highly dependent on clathrin and dynamin. Coat proteins and dynamin were not sufficient for clathrin-coated vesicle formation, and other peripheral membrane proteins recruited from the cytosol are required. The nonhydrolyzable ATP analogue, AMPPNP did not support clathrin-coated vesicle formation; however, surprisingly, GTP gamma S was as effective as GTP. This assay will provide a powerful tool to dissect the minimum machinery and to probe the hierarchy of events involved in cargo selection and endocytic clathrin-coated vesicle formation.
    Traffic 07/2003; 4(6):376-89. · 4.65 Impact Factor

Publication Stats

16 Citations
10.21 Total Impact Points

Institutions

  • 2003–2006
    • The Scripps Research Institute
      • Department of Cell and Molecular Biology
      La Jolla, CA, United States