Figure 3.

Vigabatrin treatment promotes forward-trafficking of GABA_A receptors through the secretory pathway. High-density neurons were incubated in the absence or presence of vigabatrin (VGB) (0.5 μg/μl, 37°C) for 6 h. The GABA_A receptor α1 subunit was then immunoprecipitated from neuronal lysates. Immunoprecipitated samples from each condition were then split into three equal samples and digested with either Endo H or PNGase or left undigested. Samples were resolved by SDS PAGE and analyzed by Western blotting using an anti-α1 subunit antibody. (A) A representative Western blot. Undigested samples yielded a single band at 50 kDa. Digest with PNGase, which removes all N-linked glycans, resulted in a 46 kDa band. Endo H digest produced a 48 kDa band, indicating that the α1 subunit is partially resistant to Endo H and, therefore, represents a mature (post ER) form of the α1 subunit. (B) Replicate data for immunoblot experiments described in (A). Data shown are the ratio of the Endo H resistant band to the undigested band presented as average ± SEM. *p ≤ 0.05, paired t-test, n ≥ 4.