Affinage

MIIP

Migration and invasion-inhibitory protein · UniProt Q5JXC2

Length
388 aa
Mass
42.8 kDa
Annotated
2026-06-10
26 papers in source corpus 14 papers cited in narrative 14 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

MIIP (IIp45) is a multifunctional tumor suppressor that restrains cell invasion, migration, mitotic progression, and oncogenic signaling across multiple cancer types (PMID:14617774, PMID:20008322, PMID:20418911). It was first identified as a direct binding partner of IGFBP-2 through the latter's thyroglobulin-RGD region, antagonizing IGFBP-2-stimulated glioma invasion and downregulating invasion-associated genes including NFκB targets (PMID:14617774). A central mechanism is its physical interaction with and inhibition of the deacetylase HDAC6: MIIP binds HDAC6, suppresses its enzymatic activity and stability, increases α-tubulin acetylation, and thereby inhibits migration (PMID:20008322). This HDAC6 axis is reused in distinct contexts — MIIP promotes acetylation-dependent degradation of HIF-1α (PMID:29343850), and EGF-triggered PKCε phosphorylation of MIIP at Ser303 drives its nuclear interaction with RelA/p65, where it blocks HDAC6-mediated RelA deacetylation to tune NF-κB output, with PP1 reversing this phosphorylation (PMID:29038521). MIIP also controls mitotic and chromosomal fidelity by binding Cdc20 to inhibit APC/C-mediated cyclin B1 degradation (PMID:20418911) and by suppressing topoisomerase II activity, with haploinsufficiency producing chromosomal instability (PMID:27741356). Through dedicated C-terminal and RGD/polyproline motifs, MIIP additionally competes with Rac1-GTP for PAK1 to remodel the actin cytoskeleton (PMID:27760566), facilitates PP1α-mediated AKT dephosphorylation to suppress AKT-mTOR signaling (PMID:31092266), and engages integrin β3 to drive β-catenin degradation and reduce VEGFA (PMID:36130933). Further reported activities include accelerated EGFR turnover (PMID:26824318), HSP90 acetylation-driven HIF-2α destabilization (PMID:34931765), and regulation of AZGP1 N-glycosylation (PMID:38245780).

Mechanistic history

Synthesis pass · year-by-year structured walk · 12 steps
  1. 2003 Medium

    Established MIIP's founding identity as an IGFBP-2 binding protein that suppresses invasion, answering what cellular process this uncharacterized protein controls.

    Evidence Yeast two-hybrid screen with in vitro and xenograft invasion assays and gene expression profiling in glioma

    PMID:14617774

    Open questions at the time
    • Mechanism by which IGFBP-2 binding translates to NFκB/ICAM-1 downregulation not resolved
    • Binding interface on MIIP itself not mapped
  2. 2005 Medium

    Showed that a tumor-specific frameshifted splice isoform (IIp45S) is rapidly proteasomally degraded, explaining how MIIP function may be lost in glioblastoma despite mRNA expression.

    Evidence RT-PCR, sequencing, proteasome inhibitor experiments and western blot in GBM tissues and cell lines

    PMID:15867349

    Open questions at the time
    • Functional consequence of isoform loss not directly tested
    • Degradation machinery targeting IIp45S not identified
  3. 2009 High

    Defined the HDAC6 axis, showing MIIP binds and inhibits HDAC6 to raise α-tubulin acetylation, providing a concrete molecular mechanism for migration suppression.

    Evidence Yeast two-hybrid, GST pulldown, co-IP, HDAC activity assay, domain mapping, protein turnover and siRNA epistasis

    PMID:20008322

    Open questions at the time
    • How MIIP both inhibits activity and reduces HDAC6 stability mechanistically distinct or linked is unclear
    • No structural model of the MIIP-HDAC6 interface
  4. 2010 Medium

    Linked MIIP to mitotic control by showing it binds Cdc20 and inhibits APC/C-mediated cyclin B1 degradation, establishing a cell-cycle tumor-suppressive role.

    Evidence Co-IP, in vitro interaction assay, glial-specific mouse model and growth/colony assays

    PMID:20418911

    Open questions at the time
    • Whether MIIP competes with substrates or alters Cdc20 conformation not resolved
    • Cdc20-binding region of MIIP not mapped
  5. 2016 Medium

    Expanded MIIP's mechanistic repertoire across cytoskeletal, chromosomal, and receptor pathways, showing PAK1/Rac1 competition, Topo II inhibition with chromosomal instability suppression, and accelerated EGFR turnover.

    Evidence Co-IP, Rac1 activity and deletion-construct mapping; ZFN haploinsufficiency model with karyotyping and Topo II assay; pulse-chase and inhibitor experiments for EGFR

    PMID:26824318 PMID:27741356 PMID:27760566

    Open questions at the time
    • Whether these are independent activities or share an upstream trigger is unknown
    • Direct Topo II interaction versus indirect modulation not distinguished
    • Mechanism routing EGFR to both proteasomal and lysosomal degradation unclear
  6. 2017 High

    Revealed signal-dependent regulation of MIIP, showing EGF/PKCε-driven Ser303 phosphorylation switches MIIP into a nuclear RelA-stabilizing factor, redefining MIIP as a context-dependent modulator rather than a purely inhibitory protein.

    Evidence Phosphorylation and kinase/phosphatase assays, nuclear fractionation, co-IP, and gain/loss-of-function studies

    PMID:29038521

    Open questions at the time
    • How Ser303 phosphorylation directs nuclear localization not detailed
    • Reconciliation of pro-metastatic RelA stabilization with MIIP's tumor-suppressive activities not resolved
  7. 2018 Medium

    Connected the HDAC6 axis to hypoxia signaling and established a feedback loop, showing MIIP promotes HIF-1α acetylation/degradation while HIF-1α represses MIIP via miR-646.

    Evidence ChIP, luciferase reporter, miRNA array, HDAC activity assay and co-IP with xenografts in pancreatic cancer

    PMID:29343850

    Open questions at the time
    • Whether HIF-1α acetylation is the direct consequence of HDAC6 inhibition not formally separated from other effects
    • miR-646 regulation tested in a single tumor context
  8. 2019 Medium

    Identified the PP1α-AKT mechanism, showing MIIP's C-terminus recruits PP1α to dephosphorylate AKT and suppress AKT-mTOR signaling.

    Evidence Reciprocal co-IP, co-localization, deletion mutagenesis with functional rescue and siRNA in prostate cancer with xenografts

    PMID:31092266

    Open questions at the time
    • Whether MIIP acts as a scaffold or allosteric activator of PP1α not resolved
    • Substrate selectivity of the MIIP-PP1α module not defined
  9. 2021 Medium

    Extended HSP90-chaperone control of HIF, showing MIIP promotes HSP90 acetylation to release HIF-2α for RACK1-mediated ubiquitination and degradation in renal carcinoma.

    Evidence Co-IP, ubiquitination assay, RNA-seq and xenograft models

    PMID:34931765

    Open questions at the time
    • How MIIP enhances HSP90 acetylation mechanistically (via HDAC6 or other) not stated
    • Direct versus indirect MIIP-HSP90 engagement unclear
  10. 2022 Medium

    Defined an integrin-based mechanism, showing MIIP's RGD motif binds ITGB3 to drive β-catenin degradation and reduce VEGFA, linking MIIP to angiogenesis suppression.

    Evidence Co-IP, RGD-mutant functional assays, ubiquitination assay and in vitro/in vivo assays in triple-negative breast cancer

    PMID:36130933

    Open questions at the time
    • Downstream signaling steps from ITGB3 to β-catenin not fully mapped
    • Whether RGD engagement competes with ECM ligands not tested
  11. 2024 Medium

    Uncovered a metabolic role, showing MIIP regulates AZGP1 N-glycosylation by interfering with STT3A, controlling AZGP1 secretion and adipocyte browning/lipolysis.

    Evidence Co-IP, glycosylation assays, co-culture and allograft models in colorectal cancer

    PMID:38245780

    Open questions at the time
    • How MIIP physically blocks the AZGP1-STT3A association not detailed
    • Tested in colorectal context only
  12. 2024 Low

    Proposed a structural/centriolar role, localizing MIIP to the A-C linker of centrioles in a complex with CCDC77 and WDR67 required for triplet cohesion and duplication.

    Evidence Ultrastructure expansion microscopy and depletion phenotyping (preprint)

    PMID:bio_10.1101_2024.10.04.616628

    Open questions at the time
    • Direct interaction/complex membership not confirmed by co-IP
    • Relationship between centriolar role and cytoplasmic tumor-suppressive functions unknown
    • Single preprint, not peer-reviewed

Open questions

Synthesis pass · forward-looking unresolved questions
  • How MIIP's many distinct interaction modules (HDAC6, Cdc20, PAK1, PP1α, ITGB3, HSP90, AZGP1, centriolar partners) are coordinated, prioritized, or spatially partitioned within a single cell remains unresolved.
  • No integrated model reconciling cytoskeletal, mitotic, signaling, and centriolar roles
  • No high-resolution structure of MIIP or its complexes
  • Endogenous stoichiometry and context-dependent partner selection undefined

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0098772 molecular function regulator activity 4 GO:0060090 molecular adaptor activity 3
Localization
GO:0005856 cytoskeleton 2 GO:0005634 nucleus 1
Pathway
R-HSA-162582 Signal Transduction 3 R-HSA-1640170 Cell Cycle 2 R-HSA-8953897 Cellular responses to stimuli 2
Complex memberships
APC/C (via Cdc20 interaction)centriolar A-C linker (with CCDC77, WDR67)

Evidence

Reading pass · 14 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2003 IIp45 (MIIP) protein binds directly to IGFBP-2 through the thyroglobulin-RGD region of the C terminus of IGFBP-2, as identified by yeast two-hybrid screen, and inhibits IGFBP-2-stimulated glioma cell invasion in vitro and in xenograft models. IIp45 consistently inhibited expression of invasion-associated genes including NFκB and its downstream target ICAM-1. Yeast two-hybrid screen, functional invasion assays (in vitro and xenograft), gene expression profiling Proceedings of the National Academy of Sciences of the United States of America Medium 14617774
2009 IIp45/MIIP physically interacts with HDAC6 (requiring both catalytic domains of HDAC6 for binding), inhibits HDAC6 enzymatic activity, reduces HDAC6 protein stability, increases acetylated α-tubulin levels, and thereby inhibits cell migration. Knockdown of HDAC6 reversed the increased migration caused by MIIP siRNA knockdown. Yeast two-hybrid, GST pulldown, co-immunoprecipitation, HDAC activity assay, protein turnover assay, siRNA epistasis The Journal of biological chemistry High 20008322
2010 MIIP interacts directly with Cdc20 and inhibits APC/C-mediated degradation of cyclin B1, thereby attenuating mitotic transition and increasing mitotic catastrophe. This mechanism contributes to inhibition of glioma development in a mouse model. Co-immunoprecipitation, in vitro interaction assay, mouse glial-specific model, colony formation and cell growth assays, siRNA knockdown Oncogene Medium 20418911
2005 A tumor-specific alternatively spliced isoform of IIp45 (IIp45S), resulting from exclusion of exon 7 and encoding a frameshifted C-terminus, is expressed in 60% of GBM tissue samples and 100% of GBM cell lines but not in normal organs. The IIp45S protein is undetectable despite mRNA expression because it is rapidly degraded by the ubiquitin-proteasome mechanism. RT-PCR, sequencing, proteasome inhibitor experiments, western blot Cancer research Medium 15867349
2016 MIIP attenuates Rac1 signaling in endometrial cancer by competing with Rac1-GTP for binding to the p21-binding domain of PAK1. MIIP and PAK1 bind each other through a C-terminal polyproline domain of MIIP, and deletion of this PAK1-binding domain reduces MIIP's cell migration-inhibiting activity. Elevated MIIP expression reduces lamellipodia formation. Co-immunoprecipitation, Rac1 activity assay, serial deletion constructs, immunofluorescence (F-actin), transwell migration assay Journal of hematology & oncology Medium 27760566
2016 MIIP haploinsufficiency inhibits topoisomerase II (Topo II) activity and induces chromosomal missegregation, and also alters stability of APC/CCdc20 downstream proteins securin and cyclin B1, thereby acting as a chromosomal instability suppressor in colorectal cancer. Zinc finger nuclease-mediated gene deletion (haploinsufficiency), spectral karyotyping, topoisomerase II activity assay, western blot, in vivo xenograft The Journal of pathology Medium 27741356
2016 MIIP overexpression reduces steady-state EGFR protein levels in lung cancer cells by accelerating EGFR protein turnover through both proteasomal degradation in the endoplasmic reticulum and lysosomal degradation after endocytic trafficking, leading to inhibition of downstream Ras/MEK signaling and cell proliferation. Pulse-chase with 35S-methionine, proteasome and lysosome inhibitor experiments, western blot, overexpression/knockdown, downstream signaling assays Oncotarget Medium 26824318
2017 EGF stimulation induces PKCε-dependent phosphorylation of MIIP at Ser303. This phosphorylation promotes MIIP interaction with RelA/p65 in the nucleus, where MIIP prevents HDAC6-mediated deacetylation of RelA, thereby enhancing RelA transcriptional activity and facilitating tumor metastasis. PP1 phosphatase mediates dephosphorylation of MIIP-S303. Phosphorylation assays, co-immunoprecipitation, nuclear fractionation, PKCε kinase assay, PP1 phosphatase assay, loss-of-function and gain-of-function studies Nature communications High 29038521
2018 MIIP suppresses HDAC6 deacetylase activity to promote acetylation and subsequent degradation of HIF-1α, thereby impairing HIF-1α accumulation in pancreatic cancer cells. Conversely, HIF-1α indirectly downregulates MIIP at the post-transcriptional level by activating transcription of miR-646, which targets MIIP mRNA coding sequence and impairs its stability. ChIP, luciferase reporter assay, miRNA array, overexpression/knockdown, HDAC activity assay, co-immunoprecipitation, xenograft models Oncogene Medium 29343850
2019 MIIP interacts with PP1α via its C-terminal part and facilitates PP1-mediated AKT dephosphorylation, thereby inhibiting AKT-mTOR signaling and prostate cancer cell growth. A C-terminal deletion mutant of MIIP (MIIPΔC) that cannot interact with PP1α loses this inhibitory function, and silencing PP1α reverses MIIP's inhibitory effect on AKT phosphorylation. Co-immunoprecipitation, immunofluorescence co-localization, western blot, deletion mutagenesis, siRNA knockdown, xenograft model Cell communication and signaling : CCS Medium 31092266
2021 MIIP promotes HSP90 acetylation and impairs its chaperone function toward HIF-2α in clear cell renal cell carcinoma, leading to RACK1 binding HIF-2α and causing its ubiquitination and proteasomal degradation, consequently decreasing transcription of the HIF-2α target CYR61 and inhibiting proliferation and angiogenesis. Co-immunoprecipitation, ubiquitination assay, RNA-sequencing, overexpression/knockdown, xenograft model, western blot, ELISA Cancer biology & medicine Medium 34931765
2022 MIIP directly interacts with integrin β3 (ITGB3) through its RGD motif, suppresses ITGB3 downstream signaling, elevates ubiquitin-mediated β-catenin degradation, reduces VEGFA production, and inhibits EMT, thereby suppressing angiogenesis and tumorigenesis in triple-negative breast cancer. Co-immunoprecipitation, RGD-mutant functional assays, ubiquitination assay, in vitro and in vivo functional assays Cell death & disease Medium 36130933
2024 MIIP interacts with the lipid mobilization factor AZGP1 and regulates its N-glycosylation by interfering with its association with the glycosyltransferase STT3A. MIIP downregulation promotes STT3A-mediated N-glycosylation and oversecretion of AZGP1, which then induces adipocyte browning and lipolysis through the cAMP-PKA pathway in colorectal cancer. Co-immunoprecipitation, glycosylation assays, in vitro co-culture model, in vivo allograft model, western blot Cell & bioscience Medium 38245780
2024 MIIP localizes between microtubule triplets at the A-C linker of centrioles, forming a complex with CCDC77 and WDR67. Depletion of A-C linker components including MIIP disrupts microtubule triplet cohesion, causing breakage at the proximal end of centrioles. The A-C linker (including MIIP) also plays a role in centriole duplication through torus regulation. Ultrastructure expansion microscopy, protein depletion (siRNA/knockdown), co-localization studies bioRxivpreprint Low bio_10.1101_2024.10.04.616628

Source papers

Stage 0 corpus · 26 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2003 IIp45, an insulin-like growth factor binding protein 2 (IGFBP-2) binding protein, antagonizes IGFBP-2 stimulation of glioma cell invasion. Proceedings of the National Academy of Sciences of the United States of America 76 14617774
2009 IIp45 inhibits cell migration through inhibition of HDAC6. The Journal of biological chemistry 49 20008322
2018 MiRNA-646-mediated reciprocal repression between HIF-1α and MIIP contributes to tumorigenesis of pancreatic cancer. Oncogene 48 29343850
2017 PKCε phosphorylates MIIP and promotes colorectal cancer metastasis through inhibition of RelA deacetylation. Nature communications 41 29038521
2010 Inhibition of gliomagenesis and attenuation of mitotic transition by MIIP. Oncogene 37 20418911
2020 MIIP inhibits EMT and cell invasion in prostate cancer through miR-181a/b-5p-KLF17 axis. American journal of cancer research 24 32195032
2016 MIIP remodels Rac1-mediated cytoskeleton structure in suppression of endometrial cancer metastasis. Journal of hematology & oncology 23 27760566
2005 Inactivation of the invasion inhibitory gene IIp45 by alternative splicing in gliomas. Cancer research 23 15867349
2011 MIIP, a cytoskeleton regulator that blocks cell migration and invasion, delays mitosis, and suppresses tumorogenesis. Current protein & peptide science 22 21190522
2016 MIIP accelerates epidermal growth factor receptor protein turnover and attenuates proliferation in non-small cell lung cancer. Oncotarget 17 26824318
2016 MIIP haploinsufficiency induces chromosomal instability and promotes tumour progression in colorectal cancer. The Journal of pathology 16 27741356
2010 Definition of a functional single nucleotide polymorphism in the cell migration inhibitory gene MIIP that affects the risk of breast cancer. Cancer research 16 20103646
2019 MIIP inhibits the growth of prostate cancer via interaction with PP1α and negative modulation of AKT signaling. Cell communication and signaling : CCS 13 31092266
2022 MIIP functions as a novel ligand for ITGB3 to inhibit angiogenesis and tumorigenesis of triple-negative breast cancer. Cell death & disease 12 36130933
2019 Upregulation of MIIP regulates human breast cancer proliferation, invasion and migration by mediated by IGFBP2. Pathology, research and practice 12 31078343
2024 MIIP downregulation drives colorectal cancer progression through inducing peri-cancerous adipose tissue browning. Cell & bioscience 10 38245780
2015 Altered expression and loss of heterozygosity of the migration and invasion inhibitory protein (MIIP) gene in breast cancer. Oncology reports 10 25873164
2021 MIIP inhibits clear cell renal cell carcinoma proliferation and angiogenesis via negative modulation of the HIF-2α-CYR61 axis. Cancer biology & medicine 9 34931765
2021 idenPC-MIIP: identify protein complexes from weighted PPI networks using mutual important interacting partner relation. Briefings in bioinformatics 8 32065215
2024 VNP20009-Abvec-Igκ-MIIP suppresses ovarian cancer progression by modulating Ras/MEK/ERK signaling pathway. Applied microbiology and biotechnology 6 38372808
2020 MIIP inhibits malignant progression of hepatocellular carcinoma through regulating AKT. European review for medical and pharmacological sciences 5 32196585
2016 MIIP expression predicts outcomes of surgically resected esophageal squamous cell carcinomas. Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine 5 26825982
2015 DNA studies of newly synthesized heteroleptic platinum(II) complexes [Pt(bpy)(iip)](2+) and [Pt(bpy)(miip)](2.). Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry 5 26626200
2018 MIIP is downregulated in gastric cancer and its forced expression inhibits proliferation and invasion of gastric cancer cells in vitro and in vivo. OncoTargets and therapy 4 30588008
2018 [Expression and clinical significance of MIIP and PAK1 in endometrial carcinoma]. Zhonghua zhong liu za zhi [Chinese journal of oncology] 1 29860763
2021 Erratum: MIIP is Downregulated in Gastric Cancer and Its Forced Expression Inhibits Proliferation and Invasion of Gastric Cancer Cells in vitro and in vivo [Corrigendum]. OncoTargets and therapy 0 33986600

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