FIGURE 1.

TID1 physically interacts with frataxin both in vivo in mouse cortex and in vitro in cortical neurons. In both cortical homogenates (A) and neuronal lysates (B), frataxin was immunoprecipitated by a TID1L/S antibody but not control IgG. Similarly, a specific TID1L antibody but not control IgG immunoprecipitated frataxin from cortical homogenates (C) and HEK293 cells (D) but to a much lesser extent. In an in vitro binding assay, purified glutathione S- transferase (GST)-frataxin but not purified GST pulled down TID1L (E). In HEK293 cells transfected with frataxin-HA and TID1S-Flag, immunofluorescence was performed using anti-HA and anti-Flag antibodies. Frataxin colocalized with TID1S (F). Frataxin also colocalized with endogenously expressed TID1L stained with an anti-TID1L antibody (F), further supported the interaction between TID1 and frataxin.