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FLASH GENE
Symbol SYNJ1 contributors: mct/npt - updated : 04-01-2015
HGNC name synaptojanin 1
HGNC id 11503
DNA
TYPE functioning gene
STRUCTURE 103.08 kb     32 Exon(s)
10 Kb 5' upstream gene genomic sequence study
MAPPING cloned Y linked N status confirmed
RNA
TRANSCRIPTS type messenger
identificationnb exonstypebpproduct
ProteinkDaAAspecific expressionYearPubmed
32 splicing 7075 173.1 1570 nonneuronal ubiquitously expressed 2006 17158794
present at all stages of clathrin-coated pit formation
32 splicing 7099 144.86 1311 predominant isoform expressed in the brain 2006 17158794
rapidly recruited as a "burst," together with endophilin, at a late stage of clathrin-coated pits formation
28 - 6942 - 1526 - 2006 17158794
32 - 7059 1432.25 1295 - 2006 17158794
EXPRESSION
Type
   expressed in (based on citations)
organ(s)
SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
Endocrineneuroendocrinepituitary  predominantly
Nervousbrain   highly
 nervecranial nerve  moderately
Reproductivefemale systemplacenta  highly
 male systemprostate   
Visualeyeretina    Danio rerio
tissue
SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
Blood / hematopoieticbone marrow   
Connectivebone   
Nervouscentral   
cells
SystemCellPubmedSpeciesStageRna symbol
Visualcone photoreceptor Danio rerio
cell lineage
cell lines
fluid/secretion
at STAGE
physiological period embryo, pregnancy
Text developing brain, placenta
PROTEIN
PHYSICAL PROPERTIES
STRUCTURE
motifs/domains
  • N-terminal Sac1 phosphatase domain
  • a central 5- phosphatase domain
  • a C-terminal proline-rich domain with catalytic activity required for normal synaptic vesicle internalization and reavailability (Mani 2007)
  • a SAC1 like phosphatase domain
  • one RNA recognition motif (RRM)
  • a C terminal proline-rich region
  • HOMOLOGY
    interspecies homolog to rattus Synj1 (90.4 pc)
    homolog to murine Synj1 (90.4 pc)
    Homologene
    FAMILY
  • inositol-1, 4, 5-triphosphate 5-phosphatase family
  • CATEGORY enzyme , transport
    SUBCELLULAR LOCALIZATION     intracellular
    intracellular,cytoplasm,cytosolic,vesicle
    text
  • secretory vesicles
  • mostly expressed in the synaptic terminals of neurons (Herrera 2009)
  • basic FUNCTION
  • polyphosphoinositide phosphatase, key factor controlling the level of PtdIns(4,5)P2 required for proper neurotransmission
  • playing an essential role in synaptic vesicle recycling
  • acting as a negative regulator of clathrin coats
  • playing a role in neurological manifestations in Down syndrome
  • also required for normal vesicle endocytosis (Mani 2007)
  • playing a critical role for retrieval of membrane in order to maintain the quantity, timing of fusion, and spontaneous release properties of synaptic vesicles at hair-cell ribbon synapses
  • major regulators of inositol metabolism and signaling in the brain and involved in astrogliogenesis
  • may have a possible role for astrocytes or astrogliogenesis in Doiwn syndrome
  • polyphosphoinositide phosphatase involved in clathrin-mediated endocytosis in conventional synapses
  • acts with membrane curvature generators/sensors, such as the BAR protein endophilin, to preferentially remove PI(4,5)P2 from curved membranes as opposed to relatively flat ones
  • key regulator of the signalling phospholipid phosphatidylinositol-4,5-biphosphate that regulate clathrin-mediated endocytosis
  • involvement of SYNJ1 in endosomal abnormalities is consistent with the finding that the 145 kDa isoform interacts with endocytic SH3 domain-containing proteins, such as endophilin, amphiphysin and intersectin
  • CELLULAR PROCESS protein
    PHYSIOLOGICAL PROCESS endocytosis transport
    text synaptic vesicle endocytosis
    PATHWAY
    metabolism other
    signaling
    phosphate metabolism
    a component
    INTERACTION
    DNA
    RNA binding
    small molecule nucleotide,
    protein
  • binding to EPS15 (a clathrin coat-associated protein) via a C-terminal domain containing three Asn-Pro-Phe (NPF) repeats
  • binding to a variety of SH3 domain-containing proteins including AMPH, SH3GL1, SH3GL2, SH3GL3 and GRB2 via the C-terminal proline-rich region
  • intersection (ITSN)
  • Sh3p4
  • GRB2
  • directly interact with one another to regulate synaptic vesicle endocytosis and recycling
  • EPS15 (a clathrin coat-associated protein)
  • interacting with DYRK1A (involved in regulating the recruitment activity but not the phosphatase activity of SYNJ1)
  • SYNJ1 and PACSIN1 are potential substrates of PAK7
  • cell & other
    REGULATION
    inhibited by cyclin-dependent kinase 5 (Cdk5) phosphorylation
    Phosphorylated by PAK7 (phosphorylation promotes the interaction of SYNJ1 with PACSIN1, implicating PAK7 in synaptic vesicle trafficking)
    ASSOCIATED DISORDERS
    corresponding disease(s) PARK20 , EIEE53
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional     --over  
    may affect a variety of synaptic processes, particularly in brain regions normally exhibiting the highest levels of expression, such as the hippocampus
    constitutional     --over  
    contribution of SYNJ1 overexpression to the endosomal changes observed in Down syndrome
    Susceptibility
    Variant & Polymorphism
    Candidate gene for bipolar disorder
    Marker
    Therapy target
    SystemTypeDisorderPubmed
    neurologyneurodegenerativealzheimer
    SYNJ1 reduction ameliorates Alzheimer disease -associated behavioral and synaptic deficits, providing evidence that SYNJ1 and, more generally, phosphoinositide metabolism may be promising therapeutic targets
    mental retardationtrisomy 
    attractive new target for rescuing endocytic dysfunction and lipid metabolism in Down syndrome
    neurologyneurodegenerativealzheimer
    attractive new target for rescuing endocytic dysfunction and lipid metabolism in AD
    ANIMAL & CELL MODELS
  • Synj1-/- mice display elevated steady-state levels of PIP2 with an accumulation of clathrin-coated vesicles in nerve terminals, and these animals die shortly after birth
  • presence of enlarged endosomes in the cortex of transgenic mice overexpressing Synj1