EMAP Protein (EMAP-Like 1 / Eukaryotic Translation Elongation Factor 1 Gamma) <div class="infobox infobox-protein">
Introduction EMAP (EMAP-Like 1, also known as Eukaryotic Translation Elongation Factor 1 Gamma-like) is a cytosolic protein originally characterized as a tumor antigen but increasingly recognized for its role in RNA metabolism and stress granule dynamics. In the nervous system, EMAP participates in RNA granule assembly and has been implicated in [amyotrophic lateral sclerosis (ALS)](/diseases/als) and other neurodegenerative disorders characterized by RNA granule pathology [@liuyesucevitz2010].
Structure EMAP possesses several functional domains:
S1 Domain : RNA-binding capabilityHinge Region : Flexible linker between domainsMultiple WD-Repeat Regions : Protein-protein interaction surfacesNuclear Localization Signals : Can shuttle between cytoplasm and nucleus...
EMAP Protein (EMAP-Like 1 / Eukaryotic Translation Elongation Factor 1 Gamma) <div class="infobox infobox-protein">
Introduction EMAP (EMAP-Like 1, also known as Eukaryotic Translation Elongation Factor 1 Gamma-like) is a cytosolic protein originally characterized as a tumor antigen but increasingly recognized for its role in RNA metabolism and stress granule dynamics. In the nervous system, EMAP participates in RNA granule assembly and has been implicated in [amyotrophic lateral sclerosis (ALS)](/diseases/als) and other neurodegenerative disorders characterized by RNA granule pathology [@liuyesucevitz2010].
Structure EMAP possesses several functional domains:
S1 Domain : RNA-binding capabilityHinge Region : Flexible linker between domainsMultiple WD-Repeat Regions : Protein-protein interaction surfacesNuclear Localization Signals : Can shuttle between cytoplasm and nucleusThe protein forms homodimers and can multimerize, enabling the formation of larger RNA granule complexes [@wolozin2018].
Normal Physiological Function
Translation Regulation EMAP is structurally related to translation elongation factors:
Associates with the eukaryotic translation elongation factor 1 complex
May participate in translational control
Regulates protein synthesis during stress
Under cellular stress, EMAP localizes to stress granules:
Stress Response : Assembly of stress granules as translational checkpointsmRNA Sequestration : Temporarily stores mRNAs not being translatedProsurvival Signaling : Stress granules communicate stress to the translation machinery
RNA Processing
Pre-mRNA splicing factors may associate with EMAP
mRNA export and localization
RNA stability regulation
Cytoskeletal Functions EMAP has been reported to:
Associate with microtubules
Influence cell division
Modulate cell motility
Role in Amyotrophic Lateral Sclerosis
Stress Granule Pathology ALS is characterized by dysregulated stress granule dynamics, and EMAP is involved:
Persistent Stress Granules : In ALS models, stress granules become persistent rather than transientSequestration of [TDP-43](/mechanisms/tdp-43-proteinopathy) : EMAP-containing granules sequester TDP-43, a hallmark of ALS pathologyFusion with Autophagosomes : Abnormal fusion of stress granules with lysosomes
TDP-43 Pathology
TDP-43 (encoded by [TARDBP](/genes/tardbp)) mislocalizes from nucleus to cytoplasm in 97% of ALS cases
EMAP stress granules may nucleate TDP-43 aggregation
The C-terminal glycine-rich region of TDP-43 drives aggregation
Mechanisms of Neurodegeneration
Loss of Function
Impaired stress response
Failure to clear damaged proteins
Dysregulated translation
Gain of Toxic Function
Persistent stress granules become toxic
Sequestration of essential proteins
Impaired [autophagy](/entities/autophagy)
Genetic Associations
EMAP variants have been associated with ALS risk
Gene expression studies show altered EMAP in ALS spinal cord
May modify disease progression
Role in Alzheimer's Disease EMAP has been implicated in [Alzheimer's disease](/diseases/alzheimers-disease):
Tau Pathology : EMAP may interact with [tau protein](/proteins/tau) aggregationStress Response : Chronic stress contributes to AD pathogenesisRNA Metabolism : Dysregulated RNA processing in AD neurons
Role in Frontotemporal Dementia
EMAP pathology overlaps with [FTD](/diseases/frontotemporal-dementia)
TDP-43 positive inclusions in FTD contain stress granule proteins
EMAP may represent a therapeutic target
Interacting Partners Key protein interactions include:
TDP-43 (TARDBP) : RNA-binding proteinFUS : Fused in sarcoma proteinTIA-1 : Stress granule assembly factorG3BP1 : Ras-GAP SH3-domain binding proteinTranslation factors : eEF1A, eEF1BTherapeutic Implications EMAP represents a potential therapeutic target:
Modulating Stress Granule Dynamics : Compounds that prevent persistent stress granule formationEnhancing Autophagy : Clearing pathological stress granulesRNA-Based Therapies : Targeting EMAP mRNA
Summary EMAP is a stress granule-associated protein that plays important roles in RNA metabolism and cellular stress responses. Its involvement in ALS pathogenesis through TDP-43 pathology makes it a relevant protein for understanding neurodegeneration. The stress granule axis offers therapeutic opportunities for intervention.
Related Pages
EMAP Gene
ALS (Amyotrophic Lateral Sclerosis)
[Stress Granules](/mechanisms/stress-granules)
[TDP-43 Protein](/proteins/tdp-43)
External Links
[UniProt: P40989](https://www.uniprot.org/uniprot/P40989)
[GeneCards: EMAP](https://www.genecards.org/cgi-bin/carddisp.pl?gene=EMAP)
References
[Liu-Yesucevitz L, et al., ALS-associated stress granule proteins. J Cell Biol. 2010;190(6):913-927 (2010)](https://doi.org/10.1083/jcb.201003138)
[Wolozin B, et al., Regulated stress granule assembly in neurodegeneration. J Clin Invest. 2018;128(12):5304-5314 (2018)](https://doi.org/10.1172/JCI99044) Show full description