Synaptojanin 1 (SYNJ1) Antibody – Mouse Monoclonal

Function: Inositol 5-phosphatase which has a role in clathrin-mediated endocytosis.

Catalytic activity: 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 4-phosphate + phosphate.

Subunit structure: Interacts with ASH/GRB2. Interacts with PACSIN1, PACSIN2 and PACSIN3

By similarity. Binds AMPH, SH3GL1, SH3GL2 and SH3GL3. Interacts with MYO1E (via SH3 domain). Ref.4 Ref.5

Subcellular location: Cytoplasm

By similarity.

Tissue specificity: Isoform 1 is found in neonatal brain, and in a wide variety of adult non-neuronal tissues. Isoform 2 is expressed predominantly in the neurons, but is also found in all other tissues at much lower levels. Isoform 1 and isoform 2 are detected in the lung and heart. Isoform 1 is expressed at higher levels than isoform 2 in the testis and liver and both isoforms are not detected in the skeletal muscle. Isoform 3 with the 16-amino-acid insert is only found in the brain while isoform 3 without the 16-amino-acid insert is found in the lung.

Developmental stage: At embryonic day 12 (E12) only isoform 1 is seen while at E16 and E18 isoform 1 and isoform 2 are seen. In the adult brain expression of isoform 2 increases dramatically as compared with its expression in embryonic brain where as isoform 1 decreases to undetectable levels.

Domain: Binds to EPS15 (a clathrin coat-associated protein) via a C-terminal domain containing three Asn-Pro-Phe (NPF) repeats

By similarity.The C-terminal proline-rich region mediates binding to a variety of SH3 domain-containing proteins including AMPH, SH3GL1, SH3GL2, SH3GL3 and GRB2.Splicing of the SAC1 domain does not alter the catalytic activity of synaptojanin 1.

Sequence similarities: Belongs to the synaptojanin family.In the central section; belongs to the inositol 1,4,5-trisphosphate 5-phosphatase family.Contains 1 RRM (RNA recognition motif) domain.Contains 1 SAC domain.