Figure 4.

Hsc70 is in large excess of clathrin in brain cytosol. A, Quantitative Western blots were performed to determine the content of clathrin, Hsc70, Hsp110, or Bag1 in bovine brain cytosol in the presence of calibrated standards of each protein, as well as a purified CCV control enriched in clathrin (Pearse, 1975; Blondeau et al., 2004). Note that there are two isoforms of Hsp110 (Ishihara et al., 1999) and three isoforms of Bag1 (Cutress et al., 2003). Bands were quantified separately by densitometry and summed for each protein in the analysis shown in B. B, Quantitative analysis of clathrin, Hsc70, Hsp110, and Bag 1 in brain cytosol. The bars represent the mean of the respective protein amounts in micrograms/milligram of total protein ± SEM from 5 to 13 independent experiments. Asterisks indicate statistical significance using ANOVA.