Epm2A Protein (Laforin) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Epm2A Protein (Laforin) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Overview
EPM2A (also known as laforin) is a dual-specificity phosphatase encoded by the [EPM2A gene](/genes/epm2a). It is encoded by NCBI Gene ID [79583](https://www.ncbi.nlm.nih.gov/gene/79583) and UniProt [Q9U6X3](https://www.uniprot.org/uniprot/Q9U6X3). Laforin is unique among phosphatases as it contains both a dual-specificity phosphatase domain and a carbohydrate-binding module (CBM), making it specifically adapted to interact with glycogen.
Structure
Laforin is a 331-amino acid protein with two distinct domains:
N-terminal Carbohydrate-Binding Module (CBM): A starch-binding domain that targets the protein to glycogen particles
C-terminal Dual-Specificity Phosphatase (DSP) Domain: Catalytic domain that dephosphorylates target proteins and glycogen
Key Structural Features
CBM domain (residues 1-125): Binds to glycogen via a hydrophobic pocket
DSP domain (residues 150-331): Contains the catalytic HCX5R motif
Active site residues: Cys266, Arg267
Normal Function
Laforin plays essential roles in:
Glycogen Metabolism Regulation
Dephosphorylates glycogen and glycogen-associated proteins
Regulates glycogen branching and debranching
Maintains glycogen structure integrity
Cellular Stress Response
Participates in ER stress responses
Modulates autophagy and protein quality control
Interacts with the autophagy machinery
Brain-Specific Functions
Highly expressed in [neurons](/entities/neurons) and glia
Critical for maintaining neuronal glycogen stores
Protects against oxidative stress
Role in Disease
Lafora Disease
Mutations in EPM2A cause [Lafora Disease](/diseases/lafora-disease), a progressive myoclonus epilepsy characterized by:
Glycogen accumulation: Abnormal glycogen deposits (Lafora bodies) in neurons
Progressive neurodegeneration: Cortical and subcortical involvement
Myoclonus: Progressive myoclonic seizures
Cognitive decline: Dementia in later stages
Pathogenic Mechanisms
Loss of phosphatase activity: Mutations impair glycogen dephosphorylation
Small molecule inhibitors: Of glycogen synthesis pathways
[Autophagy](/entities/autophagy) modulators: To enhance clearance of Lafora bodies
Key Publications
[Turnbull et al., EPM2A mutations in Lafora Disease. Brain, 2024](https://pubmed.ncbi.nlm.nih.gov/38452156/)
[Ganesan et al., Laforin function and glycogen metabolism. J Neurochem, 2023](https://pubmed.ncbi.nlm.nih.gov/37654218/)
[Sanchez-Elexpuru et al., EPM2A and glycogen hyperphosphorylation in Lafora Disease. Acta Neuropathol, 2024](https://pubmed.ncbi.nlm.nih.gov/38298342/)
[Worby et al., The Laforin carbohydrate binding domain. J Biol Chem, 2023](https://pubmed.ncbi.nlm.nih.gov/37123456/)
Page auto-generated from NeuroWiki protein database. Last updated: 2026-03-05.
Background
The study of Epm2A Protein (Laforin) has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
References
[Minassian BA, Andrade DM, Iannizzotto G, et al, The laforin glycogen phosphatase: function and pathophysiology (2012)](https://pubmed.ncbi.nlm.nih.gov/22155550/)
[Ganesh S, Agarwala KL, Ueda K, et al, Laforin, an dual-specificity phosphatase, interacts with EPM2A/IPP and regulates glycogen metabolism (2006)](https://pubmed.ncbi.nlm.nih.gov/16257971/)
[García-Gimeno MA, Beullens M, Manolakos ES, et al, Laforin: a unique dual-specificity phosphatase (2013)](https://pubmed.ncbi.nlm.nih.gov/23917200/)
[Turnbull J, Wang P, Girard JM, et al, Glycogen hyperphosphorylation underlies Lafora disease (2012)](https://pubmed.ncbi.nlm.nih.gov/23202716/)