The Ankyrin Repeat-rich Membrane Spanning (ARMS)/Kidins220 Scaffold Protein Is Regulated by Activity-dependent Calpain Proteolysis and Modulates Synaptic Plasticity Wu, Synphen H Arévalo, Juan Carlos Neubrand, Veronika Elisabeth Zhang, Hong Arrancio, Ottavio Chao, Moses V ARMS Kidins220 Synaptic plasticity Calpain proteolysis The expression of forms of synaptic plasticity, such as thephenomenon of long-term potentiation, requires the activity-dependent regulation of synaptic proteins and synapse composition. Here we show that ARMS (ankyrin repeat-rich membrane spanning protein)/Kidins220, a transmembrane scaffold molecule and BDNF TrkB substrate, is significantly reduced in hippocampal neurons after potassium chloride depolarization. The activity-dependent proteolysis of ARMS/Kidins220 was found to occur through calpain, a calcium-activated protease. Moreover, hippocampal long-term potentiation in ARMS/Kidins220 mice was enhanced, and inhibition of calpain in these mice reversed these effects. These results provide an ex planation for a role for the ARMS/Kidins220 protein in synap tic plasticity events and suggest that the levels of ARMS/Kidins220 can be regulated by neuronal activity and calpain action to influence synaptic function. 2024-01-02T11:28:30Z 2024-01-02T11:28:30Z 2010 journal article J Biol Chem 285:40472-40478 [https://doi.org/10.1074/jbc.M110.171371] https://hdl.handle.net/10481/86479 10.1074/jbc.M110.171371 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License The American Society for Biochemistry and Molecular Biology