Fig. 2. ERICH3 protein characterization.

a Schematic depiction of ERICH3 protein isoforms. The “canonical” protein isoform encoded by the reference mRNA transcript is designated “P-1.” The UniProtKB protein ID for this isoform is “Q5RHP9-1.” The protein coding exons corresponding to each protein isoforms are shown in parentheses. Numbers of the first and last amino acids for each isoform, matching to the number of amino acids in the “canonical” protein sequence are listed above each schematic representation. “P-2” represents a putative protein isoform corresponding to the mRNA transcript variant that ends at exon 12+ in neurons. “P-3” is encoded by exon 14 which is designated “Q5RHP9-2” in UniProtKB. Antigen sequences and corresponding antibodies that target different regions of the ERICH3 protein are shown below each depiction. b Western blots which validate ERICH3 antibodies. ERICH3 protein isoforms fused with FLAG-tags were overexpressed in HEK293T cells and those protein lysates were subjected to Western blots using different ERICH3 antibodies. Anti-FLAG antibody was used to confirm that the FLAG-tagged ERICH3 isoforms had been successfully overexpressed. ERICH3 antibodies that target different regions of the amino acid sequences performed as expected in Western blot. All three antibodies detected P-1 as well as their specifically targeted isoforms. GAPDH were “blotted” as internal control. c Western blots performed using validated ERICH3 antibodies to study protein lysates from human primary neurons and SK-N-SH neuroblastoma cells, with nontagged, cDNA-overexpressed ERICH3 isoforms used as a control. “P-4” is encoded by exons 12 to 14 which corresponds to a transcript variant identified in neuroblastoma cells. Figure shown represents result from triplicate experiments.