FIGURE 2.

ARMS/Kidins220 is degraded upon KCl activation of hippocampal neurons. A, ARMS/Kidins220 is degraded upon neuronal activation by KCl. Hippocampal cultures (14–21 days in vitro) were depolarized with 50 mm KCl for the indicated times. Cell lysates were immunoblotted for ARMS/Kidins220 using antibodies against the C or N terminus and for actin as a loading control. In response to neuronal activation, 220-kDa full-length ARMS/Kidins220 as detected by both C- and N-terminal antibodies was degraded, leading to the accumulation of smaller sized fragments as detected by the N-terminal antibody (arrows), estimated to be 140 (a), 120 (b), and 85 (c) kDa. 95- and 150-kDa nonspecific bands were detected by the N-terminal antibody. B, quantification of ARMS/Kidins220 protein levels in hippocampal neurons after KCl depolarization, as detected with the C-terminal antibody, normalized to actin levels, and plotted relative to untreated control (n ≥ three independent experiments; data are represented as the means ± S.E.).