| 1998 |
Human ITSN1 encodes two isoforms by brain-specific alternative splicing: a ubiquitous short form (1220 aa) containing two EH domains, a coiled-coil region, and five SH3 domains, and a brain-specific long form (1721 aa) that additionally contains GEF, PH, and C2 domains. |
cDNA cloning, alternative splicing analysis, domain architecture characterization |
Genomics |
High |
10482960 9799604
|
| 2008 |
In Itsn1 null mice, neurons show slowed endocytosis and increased endosome size, chromaffin cells show reduced exocytosis events, and NGF levels are reduced in the septal brain region, establishing ITSN1 as a regulator of endocytosis and vesicle trafficking in vivo. |
Knockout mouse generation, live-cell imaging of endocytosis, chromaffin cell amperometry, endosome size measurement by electron microscopy, NGF ELISA |
Human molecular genetics |
High |
18676989
|
| 2008 |
In C. elegans, ITSN-1 forms a stable complex with EHS-1 (Eps15) and co-localizes with it at endocytic hotspots ~300 nm from the presynaptic density; itsn-1 null mutants accumulate large irregular vesicles and membrane-associated vesicles at these sites with reduced synaptic vesicle number and reduced NMJ event frequency. Double mutants with dab-1 (Disabled) show synthetic lethality, placing itsn-1 and ehs-1 in the same genetic pathway that functions in parallel with the clathrin-associated sorting protein Disabled. |
C. elegans genetic null mutants, electron microscopy, electrophysiology (NMJ recordings), co-immunoprecipitation, genetic epistasis (double mutants) |
Traffic |
High |
18298590
|
| 2010 |
A neuron-specific microexon (exon 20) in ITSN1 encodes five amino acids inserted at the beginning of the n-Src loop of the SH3A domain, introducing negatively charged residues toward the interaction interface; mutational analysis confirmed that translocation of these charged residues is required for interaction with dynamin 1. |
Comparative sequence analysis, structural modeling, site-directed mutagenesis, pulldown/binding assays, zebrafish expression analysis |
Biochemical and biophysical research communications |
Medium |
20659428
|
| 2011 |
A novel ITSN1 isoform (ITSN1-22a) with an alternative C-terminus (encoded by exon 22a) binds amphiphysin 1 SH3 domain and ITSN1 SH3A via its CTD; an intramolecular interaction within ITSN1-22a negatively regulates its binding to Cbl but not to dynamin 1, indicating isoform-specific binding selectivity controlled by the CTD. |
RT-PCR/cDNA cloning, co-immunoprecipitation, in vitro pulldown, Western blot |
Gene |
Medium |
21712076
|
| 2012 |
ITSN1 interacts with Epstein-Barr virus LMP2A via the SH3 domains of ITSN1 binding to proline-rich motifs in both N- and C-tails of LMP2A. Syk kinase promotes phosphorylation of ITSN1 in LMP2A-expressing cells. The Shb adaptor bridges ITSN1 to LMP2A by simultaneously binding phosphorylated LMP2A tyrosines and ITSN1 SH3 domains. |
Co-immunoprecipitation, kinase inhibitor treatment, phosphorylation assays |
Cellular signalling |
Medium |
22975684
|
| 2012 |
Yeast two-hybrid screening identified >100 new binding partners for ITSN1 and ITSN2, implicating ITSNs in regulation of Rab and Arf GTPase pathways and the DISC1 interactome; ITSN proteins also form homomeric (ITSN1-ITSN1) and heteromeric (ITSN1-ITSN2) complexes. |
High-throughput yeast two-hybrid screen, co-immunoprecipitation validation |
PloS one |
Medium |
22558309
|
| 2015 |
ITSN-1s knockdown in endothelial cells impairs clathrin-mediated and caveolae-mediated endocytosis, causing TGFβ-RI (Alk5) to be internalized via compensatory enlarged endocytic structures leading to its ubiquitylation and degradation; this shifts Alk5 signaling from Smad2/3 toward Erk1/2 activation via preferential formation of the Alk5-mSos-Grb2 complex over the Alk5-Smad-SARA complex, promoting endothelial cell proliferation. |
shRNA knockdown in cultured endothelial cells and in vivo mouse model, co-immunoprecipitation, Western blot for signaling intermediates, microparticle transfer assays |
Journal of cell science |
Medium |
25720380
|
| 2017 |
CR16 (a verprolin family member) forms complexes with ITSN1 and ITSN2 in human cell lines; overexpressed CR16 promotes co-localization of ITSN1 with F-actin in MCF-7 cells, indicating CR16 modulates ITSN1 association with the actin cytoskeleton. |
Co-immunoprecipitation, confocal immunofluorescence co-localization |
Biochemical and biophysical research communications |
Low |
28161632
|
| 2018 |
WIP (WASP-interacting protein) interacts with ITSN1; the WIP/ITSN1 complex co-localizes with RAB4-positive fast recycling endosomes, participates in transferrin receptor recycling, and promotes formation of filopodia-like protrusions in MCF-7 cells. WIP enhances N-WASP interaction with ITSN1 and promotes ITSN1/β-actin association. |
Co-immunoprecipitation, confocal co-localization, transferrin recycling assay, overexpression/knockdown morphology analysis |
Gene |
Medium |
29958948
|
| 2018 |
The E3 ubiquitin ligase AIP4/ITCH monoubiquitinates the major isoform ITSN1-s (stabilizing it) and mono- plus oligo-ubiquitinates the minor isoform ITSN1-22a (causing its proteasomal degradation), explaining the low cellular abundance of ITSN1-22a. |
Ubiquitination assays, proteasome inhibitor treatment, Western blot, co-immunoprecipitation |
FEBS letters |
Medium |
29851086
|
| 2020 |
A membrane-anchored ITSN1 DH-PH construct directly activates RhoJ GTPase and promotes endothelial cell sprouting; this is sensitive to phosphorylation by focal adhesion kinase (FAK) and independent of Cdc42 activation, defining an ITSN1/RhoJ signaling axis distinct from the known ITSN1/Cdc42 pathway. |
Gain-of-function overexpression, dominant-negative RhoJ trapping, FAK inhibitor treatment, co-immunoprecipitation, cell sprouting assay |
Biochemical and biophysical research communications |
Medium |
31980169
|
| 2020 |
ITSN1 SH3 domains interact with proline-rich motifs (PRMs) of SAM68; this interaction enhances SAM68 solubility in vitro and induces dissociation of SAM68 Nuclear Bodies (SNBs) in HeLa cells via SH3A binding to the P0 PRM. An additional SH3 domain (SH3D) of ITSN1 can bind mRNAs, suggesting ITSN1 acts as a chaperone for SAM68 within nuclear ribonucleoprotein complexes. |
In vitro binding/solubility assays, immunofluorescence/nuclear body imaging in HeLa cells, domain-mapping pulldowns |
Cellular and molecular life sciences |
Medium |
32780150
|
| 2021 |
ITSN1 determines synaptojanin1 levels within clathrin-coated vesicles (CCVs) at synapses; Sgip1/AP2 excess hinders synaptojanin1 binding to ITSN1, lowering its CCV levels. ITSN1 levels in turn are determined by Eps15 (not Eps15L1), placing ITSN1 in a regulatory hierarchy: Eps15→ITSN1→synaptojanin1 for CCV life cycle control. |
CCV purification from mouse brain, quantitative proteomics of CCV interactome, AP1/σ1B knockout mouse comparison |
Scientific reports |
Medium |
33850201
|
| 2024 |
In a Drosophila model expressing human α-synuclein, haploinsufficiency of Dap160 (ITSN1 ortholog) exacerbates α-synuclein-induced compound eye degeneration and motor deficits; in vitro assays further indicate a physical interaction between ITSN1 and α-synuclein. |
Drosophila genetic haploinsufficiency model, eye degeneration scoring, motor behavior assay, in vitro binding assay |
Cell reports |
Medium |
40056900
|
| 2026 |
Dlgap2 interacts with Itsn1 at the postsynaptic density; Dlgap2 knockdown causes specific reduction of Itsn1 via ubiquitin-mediated proteasomal degradation, resulting in synaptic deficits and autism-like behaviors in mice, defining a Dlgap2-Itsn1 regulatory axis at the synapse. |
Proteomics of postsynaptic density fraction, co-immunoprecipitation, ubiquitination assay, Dlgap2 knockdown mouse behavior |
Scientific reports |
Medium |
41673270
|
| 2024 |
Deletion of the itsn1 microexon in zebrafish produces defects in neuritogenesis, demonstrating that this alternatively spliced insert contributes a specific functional role in neuronal morphogenesis in vivo. |
CRISPR/Cas9 microexon deletion in zebrafish, neuritogenesis phenotype analysis |
bioRxivpreprint |
Low |
|