sentence: Additional analysis and controls for proteins analyzed by co-immunoprecipitation or colocalization with progranulin and prosaposin A-B ) Composite western blot of additional potential PGRN-interacting proteins using Protein A or Protein G beads conjugated with normal goat IgG , or antibodies to PGRN , PSAP , sortilin , TMEM106B , cathepsin D and beta secretase-1 ( BACE-1 ) ( panel B ) .