You are measuring the amount of Protein AAA, a protein involved in neurodegenerative diseases, in the cytoplasm of a neuronal culture by immunoprecipitation and gel electrophoresis.
Following lysis of the neurons and incubation with the antisera, you immunoprecipitate the protein and analyze it by separation on an SDS page gel followed by western blotting. Your western blot reveals that there are not one but three different protein bands.
Which of the following could account for this finding? Select ALL that apply.