Accumulation of UBQLN2 in inclusions of human HD brain but not SCA3 brain. (A) Sections from HD basal ganglia were double immunolabeled for HTT and ubiquitin, ubiquitin and UBQLN2 or ubiquitin and p62. UBQLN2, ubiquitin and p62 colocalize with HTT nuclear inclusions (N=3). B) Brain sections from SCA3 pons were double immunolabeled for ATXN3 and ubiquitin, ATXN3 and UBQLN2, or ATXN3 and p62. Ubiquitin and p62, but not UBQLN2, colocalize to SCA3 nuclear inclusions (N=1). Scale bars = 10 μm.