Furthermore, reduced SMN levels affect post-translational modifications of PFN2a: This profilin isoform is hyper-phosphorylated at multiple sites within its PLP-binding site, when SMN is depleted in cell lines and in spinal cords of a SMA mouse model (Nölle et al., 2011). The gene discussed is SMN1; the disease is proximal spinal muscular atrophy.