| 1997 |
GAK (cyclin G-associated kinase) was identified as a direct binding partner of cyclin G and CDK5. GAK contains an N-terminal Ser/Thr kinase domain and a C-terminal tensin/auxilin-like domain with a leucine zipper region. Co-immunoprecipitation and BIAcore analysis confirmed direct GAK–cyclin G interaction in vivo. |
West-Western blotting, co-immunoprecipitation, BIAcore (surface plasmon resonance) |
FEBS letters |
High |
9013862
|
| 1997 |
GAK expression peaks at G1 phase during the cell cycle, and immunoprecipitates of anti-cyclin G antibody show histone H1 kinase activity that fluctuates during the cell cycle with a peak at G1 phase, suggesting GAK is an active kinase in the cyclin G complex. |
Synchronized HeLa cell cycle analysis, kinase assay of anti-cyclin G immunoprecipitates, Northern blot |
Genomics |
Medium |
9299234
|
| 2002 |
GAK/auxilin2 is a major protein kinase in clathrin-coated vesicles (CCVs) and directly phosphorylates the AP2 medium subunit (mu2/AP2M1), both in intact CCVs and in solution, distinguishing it from CK2 which phosphorylates other CCV-associated proteins. |
Isolation of purified CCVs from porcine brain, in vitro kinase assay with CCV peripheral membrane proteins as substrate, antibody identification |
Traffic (Copenhagen, Denmark) |
High |
12010461
|
| 2005 |
Depletion of GAK by shRNA in HeLa cells inhibited receptor-mediated endocytosis (transferrin and EGF internalization), reduced clathrin-coated pits on the plasma membrane, and dramatically decreased AP2 and epsin on the plasma membrane and AP1/GGA at the trans-Golgi network, indicating GAK (together with Hsc70) mediates binding of clathrin and adaptors to membranes in addition to clathrin uncoating. |
Vector-based shRNA knockdown, fluorescence microscopy, transferrin/EGF internalization assays, dominant-negative Hsp70 expression |
Journal of cell science |
High |
16155256
|
| 2006 |
GAK is transiently recruited to clathrin-coated pits (CCPs) after dynamin, immediately before vesicle invagination. GAK recruitment depends on its PTEN-like domain, which binds phospholipids. GAK recruitment is required for Hsc70-dependent irreversible clathrin uncoating, and both vesicle budding and synchronous GAK recruitment are necessary for uncoating. |
Total internal reflectance fluorescence (TIRF) microscopy in live cells, actin depolymerization experiments, domain mapping |
Journal of cell science |
High |
16895969
|
| 2009 |
GAK is required for proper centrosome maturation and mitotic chromosome congression. GAK knockdown by siRNA caused metaphase arrest via spindle-assembly checkpoint activation, multi-aster formation due to abnormal pericentriolar material fragmentation, and GAK cooperates with clathrin heavy chain (CHC) in the same pathway during mitosis, interacting with CHC to regulate functional spindle formation. |
siRNA knockdown, immunofluorescence microscopy, cell cycle analysis, co-immunoprecipitation |
Journal of cell science |
High |
19654208
|
| 2009 |
GAK localizes in both cytoplasm and nucleus. In the nucleus, GAK forms complexes with cyclin G1, p53, clathrin heavy chain (CHC), and protein phosphatase 2A B'alpha1. CHC associates with GAK via a different domain depending on cytoplasmic vs. nuclear context. Approximately 20–30% of B'alpha1, cyclin G1, and p53 complex with nuclear GAK. |
Immunostaining, GFP-GAK ectopic expression, pull-down assays with dissected GAK fragments, co-immunoprecipitation |
Genes to cells |
Medium |
19371378
|
| 2010 |
In zebrafish, knockdown of GAK (ubiquitously expressed auxilin ortholog) increases neuronal cell specification and decreases expression of the Notch target gene Her4, placing GAK upstream of Notch-dependent neuronal patterning. GAK knockdown also caused elevated apoptosis in neural tissues. |
Morpholino-mediated knockdown in zebrafish, gene expression analysis, functional complementation with Drosophila auxilin |
BMC developmental biology |
Medium |
20082716
|
| 2011 |
Mice expressing a kinase-dead form of GAK (GAK-kd knockout) die within 30 min after birth due to respiratory/pulmonary dysfunction. Surfactant protein A was abundant within alveolar spaces of control but absent in GAK-kd mice, and E-cadherin and phosphorylated EGFR signals were abnormal, establishing that GAK kinase activity is essential for pulmonary alveolar function. |
Kinase-dead knock-in mouse model, immunohistochemistry, histological analysis |
PloS one |
High |
22022498
|
| 2014 |
Crystal structure of the GAK catalytic domain revealed it is constitutively active and can adopt a dimeric inactive state via an unusual activation segment interaction in the apo form. Nanobody co-crystallization captured distinct conformations: one nanobody (NbGAK_4) stabilized the dimeric inactive state, while another (NbGAK_1) captured a monomeric active conformation with a well-ordered activation segment. GAK is an ATP-competitive kinase. |
X-ray crystallography of GAK catalytic domain alone and in complex with nanobodies, enzyme kinetic assays |
The Biochemical journal |
High |
24438162
|
| 2015 |
The clathrin-binding domain and J-domain of GAK are sufficient for Hsc70-dependent clathrin chaperoning and uncoating. A 62-kDa fragment comprising only the clathrin-binding and J-domains rescued clathrin-dependent trafficking in GAK-knockout fibroblasts and rescued lethality from brain- or liver-specific GAK knockout in mice. The PTEN-like domain is not essential for these core chaperone functions but increases efficiency in certain tissues. |
Domain-deletion rescue experiments in knockout fibroblasts, transgenic mouse rescue of tissue-specific GAK KO, double KO (GAK + auxilin) in brain |
Journal of cell science |
High |
26345367
|
| 2015 |
Selective GAK inhibitors (isothiazolo[5,4-b]pyridines) act as type I ATP-competitive inhibitors of GAK and inhibit hepatitis C virus (HCV) at two distinct steps: viral entry and assembly, establishing that GAK kinase activity regulates HCV intracellular trafficking. |
Co-crystallization with GAK, antiviral assays, kinase inhibition assays |
Journal of medicinal chemistry |
High |
25822739
|
| 2017 |
The lncRNA OIP5-AS1 directly binds GAK mRNA in the cytoplasm, reducing GAK mRNA stability and protein abundance. Elevated GAK levels after OIP5-AS1 silencing cause aberrant mitotic spindles; simultaneous silencing of both OIP5-AS1 and GAK partially rescues the mitotic defect, placing GAK downstream of OIP5-AS1 in regulation of mitotic progression. |
RNA pulldown, mRNA stability assays, siRNA double knockdown rescue experiments, immunofluorescence of mitotic spindles |
Oncotarget |
Medium |
28472763
|
| 2017 |
GAK is phosphorylated by c-Src at Y412 and Y1149. Phosphorylated GAK (pY412/pY1149) translocates from nucleus during interphase to chromosomes at prophase/prometaphase, to centrosomes at metaphase, then back to chromosomes at telophase. Mass spectrometry and co-immunoprecipitation identified MCM3 (DNA licensing factor) as a GAK-associated protein, suggesting a c-Src–GAK–MCM3 axis in DNA replication licensing. |
Phospho-specific antibody, immunofluorescence, mass spectrometry, co-immunoprecipitation/Western blot |
Cell cycle |
Medium |
28135906
|
| 2018 |
Using a chemical genetics approach (analog-sensitive GAK), GAK was shown to phosphorylate the Na+/K+-ATPase alpha-subunit Atp1a3. GAK conditional knockout neurons (CA1 pyramidal) showed a larger resting membrane potential change upon Na+/K+-ATPase blockade (ouabain), establishing that GAK regulates Na+/K+-ATPase trafficking to the plasma membrane via phosphorylation of Atp1a3. |
Chemical genetics (analog-sensitive kinase), whole-cell patch clamp recordings, conditional knockout mice |
Life science alliance |
High |
30623173
|
| 2019 |
Live imaging siRNA screen identified GAK as required for proper spindle positioning in human cells. GAK depletion impairs astral microtubules, similar to downregulation of its interactor Clathrin, placing GAK-Clathrin interaction upstream of astral microtubule integrity during mitosis. |
Live imaging siRNA screen on fibronectin micropatterns, immunofluorescence, clathrin depletion comparison |
Nature communications |
Medium |
31253758
|
| 2021 |
GAK and PRKCD are positive regulators of PRKN-independent mitophagy, dispensable for PRKN-dependent mitophagy and starvation-induced autophagy. GAK kinase activity is required for efficient mitophagy in vitro. In vivo, knockdown of the C. elegans GAK homolog (gakh-1) significantly inhibits basal mitophagy, demonstrating evolutionary conservation. |
siRNA library screen targeting 197 lipid-binding proteins, kinase activity requirement assays, C. elegans gakh-1 knockdown, zebrafish PRKCD knockout |
Nature communications |
High |
34671015
|
| 2021 |
GAK controls lysosomal dynamics via actomyosin regulation during autophagy. GAK knockout in A549 cells impaired autophagosome–lysosome fusion and autophagic lysosome reformation, causing accumulation of enlarged autophagosomes and autolysosomes. ROCK inhibition or ROCK1 knockdown mitigated GAK-KO-mediated defects, placing GAK upstream of ROCK-actomyosin signaling in lysosomal dynamics. |
GAK CRISPR/Cas9 knockout, GAK chemical inhibition, autophagic flux analysis, live imaging of lysosomes, ROCK inhibitor rescue, ROCK1 siRNA rescue |
International journal of molecular medicine |
Medium |
34468012
|
| 2022 |
GAK activity modifies the mitochondrial network and lysosomal morphology that are required for efficient mitochondrial transport to lysosomes during PRKN-independent mitophagy, while PRKCD localizes to mitochondria and regulates ULK1-ATG13 recruitment to early autophagic structures. |
GAK/PRKCD kinase inhibition, fluorescence microscopy of mitochondrial network and lysosomes, ULK1-ATG13 recruitment assay |
Autophagy |
Medium |
35001811
|
| 2023 |
GAK/dAux (Drosophila homolog) interacts with the autophagy initiation kinase ULK1/Atg1 via its uncoating domain and regulates trafficking of Atg1 and Atg9 to autophagosomes in glia, controlling the onset of glial autophagy. Lack of GAK/dAux increases autophagosome number and size and upregulates components of the initiation and PI3K class III complexes. |
Drosophila dAux knockout/knockdown, co-immunoprecipitation of GAK with ULK1/Atg1, mouse microglia GAK loss-of-function, autophagosome imaging |
Proceedings of the National Academy of Sciences of the United States of America |
High |
37428930
|
| 2023 |
FBXO22 mediates ubiquitin-dependent proteasomal degradation of GAK in cervical cancer cells, as established by proteomics, comparison of protein decay rates in cells with altered FBXO22 abundance, proteasome inhibitor rescue, and cellular ubiquitination assays. |
Proteomics, FBXO22 overexpression/depletion, proteasome inhibitor treatment, protein decay rate comparison, cellular ubiquitination assay |
Experimental cell research |
Medium |
37442264
|
| 2025 |
GAK knockdown inhibits clathrin-coated pit (CCP) stabilization and invagination. Mutations in the J-domain of GAK that abolish Hsc70 recruitment to and activation at CCPs cause accumulation of GAK at CCPs, hinder CCP stabilization and invagination, and dramatically increase abortive (highly transient) CCPs. This establishes that GAK-Hsc70 promotes turnover and remodeling of nascent clathrin assemblies required for curvature development during clathrin-mediated endocytosis. |
GAK knockdown, J-domain mutagenesis, live TIRF microscopy tracking of CCP dynamics, quantification of abortive CCPs |
Proceedings of the National Academy of Sciences of the United States of America |
High |
40424130
|
| 2026 |
GAK antagonizes ROCK-dependent actomyosin dynamics via its intrinsically disordered region (IDR), not its kinase domain. GAK-KO cells show enhanced stress fiber formation, increased myosin light chain (MLC) phosphorylation, and increased cell migration. The GAK IDR directly interacts with ARHGEF2 (a RhoGEF), and ARHGEF2 knockdown suppresses stress fiber formation in GAK-KO cells. The GAK IDR also contributes to regulation of MLC expression. |
CRISPR/Cas9 GAK knockout, domain rescue (IDR vs kinase), co-immunoprecipitation of GAK IDR with ARHGEF2, ARHGEF2 siRNA epistasis, MLC phosphorylation assays, cell migration assays |
Journal of cell science |
High |
41995027
|