Membrane palmitoylated protein 2 is a synaptic scaffold protein required for synaptic SK2-containing channel function

TLDR: Kim et al. as mentioned in this paper showed that SK2 physically interacts with a scaffold protein called MPP2, and this allows SK2-containing channels to contribute to long-term potentiation and synaptic strengthening.

Abstract: The neurons in the brain communicate with each other by releasing chemical messengers across structures called synapses. This signaling always occurs in the same direction: at a given synapse, one neuron sends signals that bind to receptor proteins on the surface of the receiving neuron. Repeatedly signaling across a synapse strengthens it, making it easier to communicate across, and sometimes such stimulation can cause a persistent strengthening of the synapse: this is known as long-term potentiation. Changes in synaptic strength are important for learning and memory. In the synapses formed between a type of brain cell called CA1 neurons, a protein called SK2 forms part of an ion channel in the membrane of the receiving neuron and is important for synaptic strengthening and long-term potentiation. To work correctly, the SK2 channels must be precisely positioned at the synapse, but the mechanisms responsible for this positioning were not clear. Now, by experimenting with purified proteins taken from the CA1 neurons of mice, Kim et al. show that SK2 physically interacts with a scaffold protein called MPP2. Further experiments revealed that MPP2 is responsible for positioning SK2 at the synapses, and this allows SK2-containing channels to contribute to long-term potentiation and synaptic strengthening. During synaptic strengthening, it is possible that SK2 disengages from MPP2, which influences learning. The next step is to understand the processes that dictate this behavior.