 in humans , absence of fragile x mental retardation protein ( fmrp ) , an rna - binding protein , results in fragile x syndrome ( fxs ) , the most common inherited form of intellectual disability . here 
 we report through biochemical and electrophysiological studies that fmrp binds the c - terminus of the slack sodium - activated potassium channel to activate the channel . 
 the findings suggest that slack activity may provide a link between patterns of neuronal firing and changes in protein translation . 
Supplementary Material