Laforin is a cell membrane and endoplasmic reticulum-associated protein tyrosine phosphatase.
Lafora disease (LD) is the only progressive myoclonus epilepsy with polyglucosan bodies. Among conditions with polyglucosan bodies, LD is unique for the subcellular location of its polyglucosans in neuronal perikarya and dendrites and not in axons. Here we report that the protein encoded by the EPM2A gene, which is mutated in LD, localizes at the plasma membrane and the endoplasmic reticulum and that it is a functional protein tyrosine phosphatase. The significance of these findings in the epilepsy of LD and in the origin and characteristic subcellular location of Lafora bodies is discussed.
Minassian
B A
BA
Department of Paediatrics, The Hospital for Sick Children, The University of Toronto, Ontario, Canada.
Andrade
D M
DM
Ianzano
L
L
Young
E J
EJ
Chan
E
E
Ackerley
C A
CA
Scherer
S W
SW
D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics*; D002462:Cell Membrane / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D020191:Myoclonic Epilepsies, Progressive / Q000235:genetics*; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000378:metabolism*; D054558:Protein Tyrosine Phosphatases, Non-Receptor
D017027:Protein Tyrosine Phosphatases; D054558:Protein Tyrosine Phosphatases, Non-Receptor; C114990:EPM2A protein, human