Movement disorder caused by FRRS1L deficiency may be associated with morphological and functional disorders in Purkinje cells.

Ferric Chelate Reductase 1 Like (FRRS1L) protein has been identified as an auxiliary regulatory protein for the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR). FRRS1L is highly expressed in the cerebellum and other brain regions associated with the control of motor function. Loss of FRRS1L has been shown to lead to impaired synaptic transmission via AMPARs and to movement disorders. We found that deletion of the FRRS1L gene causes hyperactivity, reduced muscle strength, impaired coordination, and ataxia in mice. Deletion also impairs Purkinje cell dendritic spine formation and AMPAR expression in the cerebellum and damages the electrophysiological discharge rhythm of Purkinje cells. Cerebrospinal fluid examination and oleic acid (OA)-induced lipid accumulation monitoring in FRRS1L-knockdown SH-SY5Y cells indicated that FRRS1L deficiency could lead to aberrant metabolism of amino acids, glucose, and lipids. In summary, we found that the deletion of FRRS1L leads to impaired motor coordination and cerebellar ataxia in mice, which might be related to the reduced expression of AMPARs, metabolic deviations, and dysplastic functional defects in Purkinje cells.