PARK2 interacts with FBXW8 and is recruited into insolubility in <i>Atxn2</i>-CAG42-KIN mice.

<p>(A) In HeLa cells overexpressing Cherry-GFP-PARK2 and FBXW8-HA, pulling with anti-FBXW8 antibody resulted in the detection of FBXW8 as well as of PARK2 in Co-IP lysates, demonstrating their interaction (experiment repeated twice, representative image). (B) PARK2 interacts with FBXW8 in Co-IP samples of <i>Atxn2</i>-CAG42-KIN mice independent of the polyQ length. Lower bands represent PARK2 protein (experiment repeated once). (C) PARK2 protein level is decreased in the RIPA-soluble fraction while it is increased in the SDS-soluble fraction (8 <i>Atxn2</i>^CAG1/CAG1 mice vs. ≥ 6 <i>Atxn2</i>^CAG42/CAG42 mice).</p

FBXW8 protein levels are dysregulated in SCA2 patient material.

<p>FBXW8 expression is upregulated at the transcript level in SCA2 patient skin fibroblasts (A; 4 CTL individuals vs. 4 SCA2 patients) as well as in SCA2 patient blood samples (B; 5 CTL individuals vs. 3 SCA2 patients). (C) At the protein level FBXW8 is decreased in the RIPA-soluble fraction while it is increased in the SDS-soluble fraction in SCA2 patient fibroblasts (4 CTL individuals vs. 4 SCA2 patients).</p

FBXW8 is shifted into insolubility in <i>Atxn2</i>-CAG42-KIN mice due to interaction with expanded ATXN2.

<p>(A) Pulling either with anti-ATXN2 or anti-FBXW8 antibody, ATNX2 and FBXW8 show an interaction in the cerebellum of 18-month-old <i>Atxn2</i>-CAG42-KIN mice independent of the polyQ length (experiment repeated three times for anti-ATXN2 and once with anti-FBXW8, representative images). (B) In cerebellar tissue of 18-month-old <i>Atxn2</i>-CAG42-KIN mice FBXW8 protein level is downregulated in the RIPA-soluble fraction while it is upregulated in the SDS-soluble fraction (two independent experiments each with 4 <i>Atxn2</i>^CAG1/CAG1 vs. 4 <i>Atxn2</i>^CAG42/CAG42 mice).</p