Figure 5.

Deletion of Hsp70.1/3 does not modulate levels of SDS-insoluble fibrillar protein aggregates formed by mutant htt exon 1 in R6/2 mice. A, B, Deletion of Hsp70.1/3 does not alter the levels of EM48 reactive SDS-insoluble aggregates (normalized to GAPDH reactivity) measured with Western immunoblots in 14-week-old R6/2 brain homogenates (Student's t test p = 0.96). C, D, Treatment of brain homogenates with formic acid liberates an SDS-resistant monomeric/oligomeric mutant huntingtin exon 1 species. The levels of formic acid-sensitive monomers/oligomers (normalized to GAPDH reactivity) appeared to increase in the absence of Hsp70.1/3, but did not reach statistical significance (Student's t test p = 0.15). E, F, The levels of SDS-insoluble EM48-positive fibrillar aggregates in brain measured by a filter-trap assay do not change in the absence of Hsp70.1/3 (Student's t test p = 0.89). G, H, Formic acid-treated brain homogenates were subjected to the filter-trap assay, which showed no change in EM48 immunoreactivity in the absence of Hsp70.1/3 (Student's t test p = 0.90). I, A native agarose gel used to examine EM48 immunoreactive oligomeric species in R6/2 brain homogenates shows no apparent change in the absence of Hsp70.1/3.