Figure 2. Expanded C4G2 repeats are translated into polyPG .

• A
  Immunoblotting against the HA‐tag or the GAPDH of proteins extracted from HEK293 cells transfected for 24 h with 100 C4G2 repeats embedded in the human antisense C9ORF72 and fused in all three possible frames with a HA‐tag.
• B
  LC‐MS/MS spectra of the N‐terminal part of the HA‐immunoprecipitated and LysC‐digested polyPG protein expressed as in (A).
• C, D
  Immunoblotting against the GFP‐ (C) or the HA‐tag (D) or the GAPDH of proteins extracted from HEK293 cells transfected for 24 h with 3, 10, or 100 C4G2 repeats embedded in the human antisense C9ORF72 sequence fused to the GFP in the PG frame.
• E
  Scheme of human antisense C9ORF72 transcript. Expanded C4G2 repeats, AUG initiation codon, and polyPG ORF are indicated in red.