Figure 1.

The antibodies H1485 and 4F3 recognize Δtau314 proteins with specificity. Three µL of the rabbit reticulocyte lysates containing synthetic full-length 0N4R tau (fl-tau), Δtau421, or Δtau314 proteins were subjected to Western blotting. The blots were probed by the monoclonal antibody tau-13 directed against an N-terminal epitope (a.a. 20–35) of human tau (left panel) and the polyclonal antibody H1485 (middle panel) and the monoclonal antibody 4F3 (right panel), both of which targets tau epitopes ending C-terminally at D314. While tau-13 detects fl-tau (hash mark), Δtau421 (arrowhead), and Δtau314 (asterisk), both H1485 and 4F3 recognize only Δtau314 (asterisks). Notably, proteins migrating similarly as Δtau314 in samples containing Δtau421 and fl-tau in the tau-13-probed blot may represent the tau proteins of the similar size to, but different from, Δtau314. Bands other than the ~35-kDa are likely non-specific, as all these bands appear in a sample in which no tau synthesis DNA template was included. The three full-length blots were prepared from three different 10–20% Tris-Tricine precast gels, and the same exposure time was applied to the development of the three blots. There was no grouping within each blot.