SRRD localizes to aggresomes following cellular proteotoxic stress.

Abstract

A) Schematic of APEX2 proximity ligation assay with SRRD-V5-APEX2 clonal lines. B) Volcano plot of APEX2 proximity labeling mass spectrometry output, where fold change (x-axis) is plotted by significance (y-axis). Arrows indicate enrichment in +/- MG232 conditions, and each dot represents a protein. Colored dots correspond to STRING clusters in 2I. C) Clustering of top protein-protein interactions (STRING database) of top 100 proteins ranked by fold change and p-value associated with +MG132 (blue) and top associated proteins associated with -MG132 (red) conditions. Clusters generated with MCL clustering and excludes proteins with no known connections and clusters with insignificant p-values. Clusters colored based on STRING annotated GO terms. D) Enrichment analysis of ranked proteins after differential expression analysis of APEX +/- MG132 proximity labeling experiment using CORUM protein complex database. E) 293Ts expressing SRRD-mRuby3 treated with either 5μM MG132 or DMSO control for 16hrs, fixed and stained for VIM and HDAC6. F) 293Ts stably expressing SRRD-mRuby3 transfected with mClover3 control or mClover3-TDP-43 ΔNLS. G) Colocalization of mRuby3 and mClover3 in indicated protein pairs, measured in FIJI using Pearson’s correlation coefficient. Each dot represents correlation coefficient calculated for a single cell, boxes indicate median, upper, and lower quartiles. T-test p-values: SRRD-mClover:SRRD-TDP-43 = 1.055e-08; mRuby3-TDP-43:SRRD-TDP-43 = 7.305e-10.</p