| 2008 |
MOB4 (Mob3/phocein) was identified as a stable component of the STRIPAK (striatin-interacting phosphatase and kinase) complex by affinity purification/mass spectrometry. The complex contains PP2A catalytic and scaffolding subunits, striatins, STRIP1/2, CCM3, and GCK III family kinases, establishing MOB4 as part of a large PP2A-containing signaling assembly. |
Iterative affinity purification / mass spectrometry (AP-MS) |
Molecular & cellular proteomics : MCP |
High |
18782753
|
| 2011 |
Striatin binds MOB4 (Mob3) at two distinct regions: one N-terminal region including the coiled-coil domain, and one more C-terminal region including the WD-repeat domain. PP2A associates with the coiled-coil/oligomerization domain of striatin and requires striatin oligomerization. Disruption of PP2A binding to striatin causes hyperphosphorylation and activation of striatin-associated Mst3 kinase, establishing that striatin-associated PP2A negatively regulates Mst3 activity and that MOB4 is positioned proximal to both the Mst3-binding site and PP2A, consistent with a regulatory role. |
Structure-function analysis of striatin (deletions, point mutations), Co-immunoprecipitation, in-cell phosphorylation assays |
BMC biochemistry |
High |
21985334
|
| 2010 |
Drosophila MOB4 (DMob4/Phocein) regulates axonal transport, microtubule network organization, neurite elongation, and synapse formation. Loss-of-function null and hypomorphic alleles show overgrowth of synaptic boutons (similar to endocytotic mutants), defective axonal transport, and disorganized microtubule networks in neurons. Human phocein transgene rescues DMob4 mutant lethality, demonstrating conserved function. |
Null and hypomorphic allele generation, in vivo live imaging, genetic rescue with human transgene, RNAi genome-wide screen |
The Journal of neuroscience : the official journal of the Society for Neuroscience |
High |
20392941
|
| 2008 |
Drosophila Mob4 localizes to the nucleus during interphase and to spindle poles and kinetochores during mitosis. RNAi depletion of Mob4 causes kinetochore fibers (K fibers) to splay apart and fail to maintain focus at spindle poles, both in the presence and absence of functional centrosomes, establishing a role in mitotic spindle pole organization. |
RNAi knockdown, time-lapse microscopy, GFP-fusion localization |
Journal of cell science |
Medium |
18388316
|
| 2018 |
MST4 forms a complex with MOB4 in a phosphorylation-dependent manner. The overall structure of the MST4-MOB4 complex resembles that of the MST1-MOB1 complex, but diverged key interface residues allow MST4-MOB4 to disrupt MST1-MOB1 complex assembly through alternative pairing, thereby increasing YAP activity. The MST4-MOB4 complex promotes growth and migration of PANC-1 cells (pro-oncogenic), in contrast to the tumor-suppressor MST1-MOB1 complex. |
Co-immunoprecipitation, structural comparison (crystal structure-guided analysis), cell migration/proliferation assays, competitive complex disruption assay |
The Journal of biological chemistry |
High |
30072378
|
| 2021 |
Cryo-EM structure of the human STRIPAK core (PP2AA, PP2AC, STRN3, STRIP1, MOB4) was determined at 3.2-Å resolution. Unlike canonical trimeric PP2A, STRIPAK contains four copies of STRN3 forming an elongated homotetrameric scaffold that links the complex together, one PP2AA-C heterodimer, one STRIP1, and one MOB4. An inositol hexakisphosphate (IP6) was identified as a structural cofactor of STRIP1. Mutations at key subunit interfaces disrupt STRIPAK integrity and cause aberrant Hippo pathway activation. |
Cryo-EM structure determination at 3.2 Å, interface mutagenesis, Hippo pathway activity assays |
Nature structural & molecular biology |
High |
33633399
|
| 2019 |
In Drosophila, Mob4 and Cka (STRIPAK components) are required for neural stem cell (NSC) reactivation from quiescence. Increased Mob4 and Cka levels recruit PP2A/Mts into a complex with Hippo kinase, resulting in Hippo pathway inhibition and enabling NSC reactivation. MOB4 thus functions as part of a molecular switch coordinating Hippo and InR/PI3K/Akt pathways. |
Transcriptome analysis of individual NSCs, genetic loss-of-function, co-complex recruitment assay, epistasis analysis |
Cell reports |
Medium |
31167138
|
| 2020 |
In planarians, RNAi inhibition of mob4 dramatically increases posterior body length through expansion of a posterior wnt1+ signaling center in midline muscle cells. This expansion is stem cell-dependent, establishing that MOB4 (as part of STRIPAK) represses Wnt signaling for body axis scaling through control of stem cell differentiation. |
RNAi knockdown, epistasis (wnt1 RNAi epistatic to mob4 RNAi), stem cell ablation experiments |
Current biology : CB |
Medium |
31928872
|
| 2022 |
In zebrafish, loss of mob4 (nonsense mutation) causes impaired actin biogenesis resulting in sarcomere defects and reduced myofibril content, while transgenic overexpression of mob4 increases myofibril content. Genetic interaction analysis revealed that Mob4 acts through the actin-folding chaperonin TRiC to control actin biogenesis and myofibril growth. mob4 mutants also show defective microtubule networks, consistent with TRiC's role in tubulin folding. strn3-deficient mutants show similar characteristics, confirming Mob4 as a STRIPAK core component. |
Forward genetic screen, reverse genetics (nonsense mutant), transgenic overexpression, genetic interaction analysis with TRiC |
PLoS genetics |
Medium |
35737712
|
| 2022 |
MOB3A (an alias for MOB4) bypasses oncogene-induced senescence (OIS) by inhibiting Hippo/MST/LATS signaling. Constitutive membrane localization of MOB3A phenocopies OIS bypass seen with elevated YAP expression. MOB3A and MOB3C (but not canonical MOB1A/B) uniquely permit primary cell proliferation under sustained oncogene signaling. Inhibition of MOB3 family members decreases proliferation and tumor growth of cancer cell lines. |
Library screen for OIS bypass, constitutively active localization constructs, cancer cell line knockdown assays, comparison with YAP overexpression |
Molecular cancer research : MCR |
Medium |
35046109
|
| 2023 |
MOB4 KO MCF10A cells display increased collective cell migration with loss of migration orientation in a wound healing assay. Upon wound healing, MOB4 relocalizes to the front edge of leader and follower cells migrating toward the wound. The role of MOB4 in controlling collective migration requires YAP1: MOB4 KO cells fail to activate YAP1, and the phenotype is rescued by constitutively active YAP1. |
CRISPR/Cas9 knockout, wound healing assay, live imaging/relocalization, genetic rescue with constitutively active YAP1 |
Advanced science (Weinheim, Baden-Wurttemberg, Germany) |
Medium |
41276909
|
| 2025 |
Striatin-3 and MOB4 were identified as novel Rac1 interactors in Schwann cells by co-immunoprecipitation. Schwann-cell-specific ablation of striatin-3 causes defects in lamellipodia formation; conditional knockout of striatins causes a severe delay in radial sorting. Deletion of Rac1 or striatin-1/3 in Schwann cells causes defects in YAP/TAZ activation and expression of YAP/TAZ co-regulated genes (extracellular matrix receptors), placing MOB4/STRIPAK downstream of Rac1 in Hippo pathway regulation during peripheral nervous system development. |
Co-immunoprecipitation (Rac1-striatin-3/MOB4 interaction), conditional Schwann cell knockout (Cre-lox), lamellipodia/radial sorting phenotyping, YAP/TAZ phosphorylation assays |
Cell reports |
Medium |
40056414
|
| 2023 |
Proximity-dependent biotin identification (BioID) mapped the interactome of all seven human MOB proteins including MOB4. MOB4's proximity network was defined; the dataset confirmed known STRIPAK complex interactions for MOB4 and distinguished MOB4's interactome from those of other MOB family members. MOB3C (not MOB4) uniquely interacted with 7 of 10 subunits of the RNase P complex. |
BioID proximity labeling in HeLa and HEK293 cells, affinity purification-mass spectrometry validation, pre-tRNA cleavage assay |
The Journal of biological chemistry |
Medium |
37536630
|
| 2023 |
Drosophila Mob4 is required for male fertility but has no detectable role in female fertility. mob4 RNAi leads to defective spermatid individualization, absence of mature sperm in seminal vesicles, expansion of outer axonemal microtubule doublets (loss of 9+2 linkage), and defective mitochondrial organization. Depletion of STRIPAK components Strip and Cka similarly impairs male fertility. Human MOB4 transgene rescues all Drosophila mob4 RNAi phenotypes, confirming evolutionary conservation. |
RNAi knockdown, transmission electron microscopy, genetic rescue with human MOB4 transgene, parallel depletion of other STRIPAK components |
Genetics |
Medium |
37259670
|
| 2013 |
In Neurospora crassa, phosphorylation of MOB-3 (MOB4 ortholog) by the MAP kinase MAK-2 impacts the nuclear accumulation of the cell wall integrity MAP kinase MAK-1. The STRIPAK complex (containing MOB-3/HAM-2/HAM-3/HAM-4/PPG-1/PP2A-A) is assembled at the nuclear envelope and is required for MAK-1 nuclear accumulation. MAK-2-dependent phosphorylation of the N-terminus of MOB-3 is required for proper fruiting body morphology. |
Genetic/biochemical analysis, live cell imaging, phosphorylation analysis, nuclear accumulation assays |
Molecular microbiology |
Medium |
24028079
|