A novel interaction of CLN3 with nonmuscle myosin-IIB and defects in cell motility of Cln3(-/-) cells

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a pediatric lysosomal storage disorder characterized by accumulation of autofluorescent storage material and neurodegeneration which result from mutations in CLN3 The function of CLN3 a lysosomal membrane protein is currently unknown We report that CLN3 interacts with cytoskeleton-associated nonmuscle myosin-IIB Both CLN3 and myosin-IIB are ubiquitously expressed yet mutations in either produce dramatic consequences in the CNS such as neurodegeneration in JNCL patients and Cln3(-/-) mouse models or developmental deficiencies in Myh10(-/-) mice respectively A scratch assay revealed a migration defect associated with Cln3(-/-) cells Inhibition of nonmuscle myosin-II with blebbistatin in WT cells resulted in a phenotype that mimics the Cln3(-/-) migration defect Moreover inhibiting lysosome function by treating cells with chloroquine exacerbated the migration defect in Cln3(-/-) Cln3(-/-) cells traversing a transwell filter under gradient trophic factor conditions displayed altered migration further linking lysosomal function and cell migration The myosin-IIB distribution in Cln3(-/-) cells is elongated indicating a cytoskeleton defect caused by the loss of CLN3 In summary cells lacking CLN3 have defects that suggest altered myosin-IIB activity supporting a functional and physical interaction between CLN3 and myosin-IIB We propose that the migration defect in Cln3(-/-) results in part from the loss of the CLN3-myosin-IIB interaction (C) 2010 Elsevier Inc All rights reserved