Full-length, but not exon1, mhtt increases BDNF accumulation in Golgi. Wt cells and M213 and C17.2 cells were transfected with GFP, exon1–25Q-htt of exon1–103Q-htt fused to GFP (Exon1 section), or with GT–YFP or GT–YFP plus FL-17Q-htt or FL-75Q-htt (Full-length htt overexpression section). Colocalization studies of endogenous BDNF with giantin showed no difference between GFP-expressing cells and exon1-Q25-htt or exon1–103Q-htt. In contrast, colocalization of endogenous BDNF with GT–YFP showed an increased accumulation of BDNF in the Golgi apparatus in cells transfected with FL-75Q-htt with respect to FL-17Q-htt- or GT–YFP-transfected cells. mhtt cells showed an increased BDNF accumulation in the Golgi apparatus compared with wt cells (Full-length htt endogenous section). *p < 0.05; **p < 0.01.