Plays a role in neurofilament network integrity. May be involved in modulating axonal architecture during development and in the adult. In vitro, increases the susceptibility of neurofilament-H to calcium-dependent proteases. May also function in modulating the keratin network in skin. Activates the MAPK and Elk-1 signal transduction pathway (By similarity). May be a centrosome-associated protein. Interacts with MYOC; affects its secretion and its aggregation (By similarity). Associated with centrosomes in several interphase cells. In mitotic cells, localized to the poles of the spindle (By similarity). Specifically expressed in the peripheral nervous system. High expression in motoneurons of the brainstem. Also found in neurons of many other brain regions including the cerebellar cortex, thalmus, hypothalamus and CA1, CA2, CA3 and CA4 regions of the hippocampus. Phosphorylated. Phosphorylation by GRK5 appears to occur on residues distinct from the residue phosphorylated by other kinases (By similarity). Belongs to the synuclein family.