RNA-binding protein. Specifically binds to 5'-GGGGCC-3' sequence repeats in RNA. Essential for maintenance of peripheral motor neuron and skeletal muscle function. Required for normal expression and/or alternative splicing of a number of genes in spinal cord and skeletal muscle, including the neurite outgrowth inhibitor RTN4. Also contributes to normal mitochondrial respiratory function in motor neurons, via an unknown mechanism.
Subcellular locations: Nucleus, Nucleolus, Nucleus speckle
Colocalizes with RBM39 in nuclear speckles. Inhibition of RNA synthesis, or overexpression of KNOP1, induces translocation from nuclear speckles to the nucleolus.