TRAK1
Domain
The C-terminal region is required for the early endosomal and mitochondrial localization.
Function
Involved in the regulation of endosome-to-lysosome trafficking, including endocytic trafficking of EGF-EGFR complexes and GABA-A receptors (PubMed:18675823). Involved in mitochondrial motility. When O-glycosylated, abolishes mitochondrial motility. Crucial for recruiting OGT to the mitochondrial surface of neuronal processes (PubMed:24995978). TRAK1 and RHOT form an essential protein complex that links KIF5 to mitochondria for light chain-independent, anterograde transport of mitochondria (By similarity).
Involvement in disease
Developmental and epileptic encephalopathy 68
DEE68
A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE68 is an autosomal recessive form characterized by onset of twitching and/or myoclonic jerks in infancy. The disorder progresses to refractory generalized tonic-clonic seizures, often resulting in status epilepticus, loss of developmental milestones, and early death. Other features include delayed development, axial hypotonia, spasticity of the limbs, and clonus.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
O-glycosylated (PubMed:12435728, PubMed:24995978). Glycosylated by OGT; glycosylation in response to increased extracellular glucose levels is required for and leads to regulation of mitochondrial motility by OGT (PubMed:24995978).
Sequence Similarities
Belongs to the milton family.
Tissue Specificity
High expression in spinal cord and moderate expression in all other tissues and specific brain regions examined. Expressed in all cell lines examined.
Cellular localization
- Cytoplasm
- Nucleus
- Mitochondrion
- Early endosome
- Endosome
- Mitochondrion membrane
- Cytoplasm
- Cell cortex
- Predominantly associated with early endosome. The localization to early endosomes depends on its interaction with HGS/HRS (PubMed:18675823). Colocalizes with MGARP at the mitochondria (PubMed:19528298).
Alternative names
KIAA1042, OIP106, TRAK1, Trafficking kinesin-binding protein 1, 106 kDa O-GlcNAc transferase-interacting protein, Protein Milton