MYO6 and amyotrophic lateral sclerosis: Furthermore, expression of this mutant in NSC-34 cells inhibited the association of Optn with myosin VI and lead to accumulation of autophagosomes, fragmentation of neuronal Golgi apparatus and activation of ER stress.58 The p.K489E variant has been shown to cause increased cell death and deregulate autophagy in an in vitro cell model of ALS.59