Skip to main content
. Author manuscript; available in PMC: 2021 Sep 1.
Published in final edited form as: Neurobiol Dis. 2020 Jul 10;143:105016. doi: 10.1016/j.nbd.2020.105016

Figure 1. WT and mutant (P506T) UBQLN2 differ in aggregation and subcellular localization in transgenic mouse brain.

Figure 1.

A. Transgenic WT-UBQLN2 is largely diffusely located in neurons while P506T-UBQLN2 aggregates robustly across essentially all brain regions. Representative immunofluorescence in major brain regions from 3 transgenic mouse lines (3 months old) expressing FLAG-tagged WT- or P506T-UBQLN2 under control of the mouse prion promoter. Tissue sections were stained for transgenic FLAG-tagged UBQLN2 (green) and DAPI (blue). Magnified (2x) insets in cortex panel highlight punctate UBQLN2 staining. Arrows indicate puncta present in WT-hi and P506T mice that are absent in WT-low mice. Scale bars: 50 μm.

B. Mutant UBQLN2 sequesters endogenous murine UBQLN2 into the insoluble fraction. Representative Western blot of soluble and insoluble brain fractions from transgenic (two mice) and non-transgenic mice (1 mouse) probed with anti-UBQLN2 antibody. Murine UBQLN2 (arrow) and transgenic human UBQLN2 (arrow head) can be distinguished by size. The insoluble fraction of murine UBQLN2 is significantly increased in mice expressing mutant, but not WT, transgenic UBQLN2. In three independent experiments, the average insoluble/soluble ratio for murine UBQLN2 was quantified from relative band intensities (* = P< 0.05. Error bars = SEM).

C. Mutant, but not WT, UBQLN2 in transgenic mice localizes to nuclei in neuroendothelial cells. Immunofluorescence in the lateral ventricle from WT-hi and P506T mice stained for FLAG-UBQLN2 (green) and DAPI (blue) shows WT-UBQLN2 is largely cytoplasmic whereas P506T-UBQLN2 co-localizes to nuclei (coincident with DAPI). Dotted white lines outline the ventricle edge and cell nuclei (inset). Sections are from 6 month old mice. Scale bars: 50 μm.

D. P506T-UBQLN2 occasionally translocates to the nuclei of neurons in the hippocampus of transgenic mice. Immunofluorescence of the CA1 and dentate gyrus (DG) from P506T mice stained for FLAGU-BQLN2 (green) and DAPI (blue) shows P506T-UBQLN2 co-localized to nuclei (coincident with DAPI). Dotted white lines outline the cell nuclei. Scale bars: 5 μm.

E,F. TDP43 and phospho-TDP43 levels are not significantly changed in brain lysates from UBQLN2 transgenic mice.