SYNJ1

This gene encodes a phosphoinositide phosphatase that regulates levels of membrane phosphatidylinositol-4,5-bisphosphate. As such, expression of this enzyme may affect synaptic transmission and membrane trafficking. Multiple transcript variants encoding different isoforms have been found for this gene.

Full Name

Synaptojanin 1

Function

Phosphatase that acts on various phosphoinositides, including phosphatidylinositol 4-phosphate, phosphatidylinositol (4,5)-bisphosphate and phosphatidylinositol (3,4,5)-trisphosphate (PubMed:27435091).
Has a role in clathrin-mediated endocytosis (By similarity).
Hydrolyzes PIP2 bound to actin regulatory proteins resulting in the rearrangement of actin filaments downstream of tyrosine kinase and ASH/GRB2 (By similarity).

Biological Process

Biological Process brain developmentIBA:GO_Central1 Publication
Biological Process inositol phosphate dephosphorylationISS:ParkinsonsUK-UCL
Biological Process inositol phosphate metabolic processTAS:Reactome
Biological Process learningIMP:ParkinsonsUK-UCL1 Publication
Biological Process membrane organizationTAS:Reactome
Biological Process neurotransmitter transportISS:ParkinsonsUK-UCL
Biological Process phosphatidylinositol biosynthetic processTAS:Reactome
Biological Process phosphatidylinositol dephosphorylationIDA:ParkinsonsUK-UCL1 Publication
Biological Process phosphatidylinositol metabolic processISS:ParkinsonsUK-UCL
Biological Process positive regulation of endosome organizationIMP:ParkinsonsUK-UCL1 Publication
Biological Process positive regulation of gliogenesisIEA:Ensembl
Biological Process positive regulation of receptor-mediated endocytosisIEA:Ensembl
Biological Process response to cytokineIEA:Ensembl
Biological Process response to retinoic acidIEA:Ensembl
Biological Process synaptic vesicle endocytosisIGI:ParkinsonsUK-UCL1 Publication
Biological Process synaptic vesicle primingISS:ParkinsonsUK-UCL
Biological Process synaptic vesicle transportISS:ParkinsonsUK-UCL
Biological Process synaptic vesicle uncoatingISS:ParkinsonsUK-UCL

Cellular Location

Cytoplasm, perinuclear region

Involvement in disease

Parkinson disease 20, early-onset (PARK20):
An early-onset form of Parkinson disease, a complex neurodegenerative disorder characterized by bradykinesia, resting tremor, muscular rigidity and postural instability, as well as by a clinically significant response to treatment with levodopa. The pathology involves the loss of dopaminergic neurons in the substantia nigra and the presence of Lewy bodies (intraneuronal accumulations of aggregated proteins), in surviving neurons in various areas of the brain. PARK20 is characterized by young adult-onset of parkinsonism. Additional features may include seizures, cognitive decline, abnormal eye movements, and dystonia.
Developmental and epileptic encephalopathy 53 (DEE53):
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. DEE53 inheritance is autosomal recessive.