Affinage

MLF2

Myeloid leukemia factor 2 · UniProt Q15773

Round 2 corrected
Length
248 aa
Mass
28.1 kDa
Annotated
2026-04-28
49 papers in source corpus 11 papers cited in narrative 11 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

MLF2 is a ubiquitously expressed protein that functions at the intersection of nuclear envelope biology, chromatin regulation, and p53-mediated tumor suppression. MLF2 localizes to the nuclear envelope lumen where it marks aberrant nuclear pore complex (NPC) intermediates in Torsin ATPase-deficient cells, with bleb formation dependent on the transmembrane nucleoporin POM121 and occurring immediately after post-mitotic nuclear envelope reformation (PMID:32342107). MLF2 suppresses p53 stability by binding both p53 and the deubiquitinase USP7, thereby antagonizing USP7-mediated p53 deubiquitination and promoting p53 degradation, a mechanism that contributes to its oncogenic role in colorectal cancer (PMID:37438558). MLF2 undergoes CRM1-dependent nucleocytoplasmic shuttling (PMID:26673895), binds mRNA (PMID:22658674), and requires phosphorylation at serine 24 for its oncogenic activity in chronic myeloid leukemia (PMID:31831854).

Mechanistic history

Synthesis pass · year-by-year structured walk · 6 steps
  1. 1996 High

    Identification of MLF2 as a novel gene with ubiquitous expression and chromosomal mapping to 12p13 established it as a paralog of MLF1, though no leukemia-associated rearrangements were found at the MLF2 locus.

    Evidence cDNA cloning, Northern blotting, FISH mapping, and Southern blotting of leukemia cell lines

    PMID:8661158

    Open questions at the time
    • No functional role assigned
    • Protein localization undetermined
    • Relationship to leukemogenesis unclear despite chromosomal location
  2. 2012 Medium

    Discovery that MLF2 directly contacts mRNA via UV crosslinking established an unexpected RNA-binding capacity for a protein with no canonical RNA-binding domain.

    Evidence UV crosslinking followed by oligo(dT) capture and mass spectrometry in HeLa cells

    PMID:22658674

    Open questions at the time
    • Specific RNA targets unknown
    • Functional consequence of mRNA binding not determined
    • RNA-binding domain or motif not mapped
  3. 2015 Medium

    Identification of MLF2 as a CRM1-dependent nuclear export substrate revealed that the protein undergoes active nucleocytoplasmic shuttling, providing a mechanistic basis for its presence in both nuclear and cytoplasmic compartments.

    Evidence Quantitative mass spectrometry with CRM1 inhibition (leptomycin B) in human cells

    PMID:26673895

    Open questions at the time
    • Nuclear export signal not mapped within MLF2
    • Functional significance of shuttling not established
    • Whether shuttling regulates MLF2 activity unknown
  4. 2019 Medium

    Demonstrating that phosphorylation at serine 24 is required for MLF2's oncogenic activity in CML resolved how a post-translational modification controls MLF2 function in leukemogenesis.

    Evidence Phos-tag SDS-PAGE, S24A mutagenesis abolishing colony formation in vitro and leukemogenesis in a mouse survival model

    PMID:31831854

    Open questions at the time
    • Kinase responsible for S24 phosphorylation not identified
    • Downstream effectors of phospho-MLF2 in CML unknown
    • Whether S24 phosphorylation affects p53-related or NPC-related functions not tested
  5. 2020 High

    Establishing MLF2 as a luminal component of nuclear envelope blebs in Torsin-deficient cells, dependent on POM121 and representing stalled NPC intermediates, provided the first mechanistic link between MLF2, nuclear pore biogenesis, and the nuclear envelope.

    Evidence Proteomics, live-cell imaging with MLF2 reporter, genetic epistasis showing POM121 dependence and Nup358 underrepresentation

    PMID:32342107

    Open questions at the time
    • How MLF2 is recruited to the NE lumen is unknown
    • Whether MLF2 is functionally required for NPC biogenesis or is a passive marker not resolved
    • Relationship between NE bleb phenotype and Torsin-linked dystonia pathology not established
  6. 2023 High

    Discovery that MLF2 interacts with both p53 and USP7 to antagonize USP7-mediated p53 deubiquitination defined a molecular mechanism for MLF2's oncogenic activity, explaining how MLF2 promotes p53 destabilization in colorectal cancer.

    Evidence Reciprocal co-immunoprecipitation of MLF2/p53/USP7, ubiquitination assays, knockdown and overexpression with p53 stability readouts in colorectal cancer cells

    PMID:37438558

    Open questions at the time
    • Whether MLF2-USP7 interaction also affects MDM2 stability not fully dissected
    • Structural basis of the ternary complex unknown
    • Whether the p53-suppression mechanism operates in CML or other MLF2-linked cancers not tested

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include whether MLF2 plays an active functional role in NPC biogenesis versus serving as a passive marker, the identity of the kinase phosphorylating S24, the specific mRNA targets bound by MLF2, and whether its disparate roles in chromatin remodeling, p53 regulation, and nuclear envelope biology are mechanistically linked or context-dependent.
  • No structural model of MLF2 exists
  • Integration of RNA-binding, p53 regulation, NPC biology, and SWI/SNF functions into a unified model is lacking
  • In vivo genetic models (knockout mouse) have not been reported

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0098772 molecular function regulator activity 2 GO:0003723 RNA binding 1
Localization
GO:0005634 nucleus 2 GO:0005635 nuclear envelope 2
Pathway
R-HSA-1643685 Disease 3 R-HSA-1852241 Organelle biogenesis and maintenance 2
Partners
POM121TP53USP7

Evidence

Reading pass · 11 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1996 MLF2 was identified as a novel gene encoding a 248-amino-acid protein with 63% similarity and 40% identity to MLF1. Unlike the tissue-restricted MLF1, MLF2 mRNA is expressed ubiquitously. The MLF2 gene was mapped by fluorescence in situ hybridization to human chromosome 12p13, a region frequently rearranged in acute leukemias, though Southern blotting of leukemia cell DNAs failed to reveal MLF2 gene rearrangements. cDNA cloning, Northern blotting, FISH chromosomal mapping, Southern blotting Genomics High 8661158
2006 MLF2 was detected as a phosphoprotein in the human mitotic spindle, with phosphorylation sites identified by mass spectrometry, indicating MLF2 is present and phosphorylated during mitosis. Mass spectrometry-based phosphoproteomics of purified human mitotic spindles Proceedings of the National Academy of Sciences of the United States of America Low 16565220
2007 MLF2 was localized to specific subcellular compartment(s) in human cell lines by antibody-based confocal microscopy in a large-scale subcellular atlas study. Immunofluorescence confocal microscopy with protein-specific antibodies Molecular & cellular proteomics : MCP Low 18029348
2012 MLF2 was identified as an mRNA-binding protein (RBP) in human HeLa cells by systematic UV crosslinking of RBPs to RNA (interactome capture), placing MLF2 among >860 proteins that directly contact mRNA. UV crosslinking followed by oligo(dT) capture and mass spectrometry (interactome capture) Cell Medium 22658674
2014 Selective shRNA knockdown of MLF2 in breast cancer cell lines and patient-derived xenografts reduced tumor volume, lung metastases, and breast cancer stem cell (BCSC) self-renewal. RNA deep sequencing identified damaging mutations in MLF2 associated with pulmonary metastasis. Both MLF2 and RPL39 were found to affect the nitric oxide synthase (NOS) pathway and are regulated by hypoxia. shRNA knockdown, siRNA nanoparticle delivery in xenografts, RNA deep sequencing, patient biopsy analysis Proceedings of the National Academy of Sciences of the United States of America Medium 24876273
2015 MLF2 was identified as a CRM1-dependent nuclear export substrate in human cells, indicating that MLF2 undergoes CRM1-mediated nucleocytoplasmic shuttling. Quantitative mass spectrometry-based CRM1 cargo identification combined with nuclear/cytoplasmic partitioning measurements in human cells eLife Medium 26673895
2019 MLF2 plays an oncogenic role in CML and its activity requires phosphorylation at serine 24. Phosphorylation at S24 was detected by Phos-tag SDS-PAGE. Point mutation of S24 abolished the ability of MLF2 overexpression to enhance colony formation in vitro and promote leukemogenesis in vivo (mouse survival model). MLF2 expression levels correlated with proliferation, colony formation, and imatinib sensitivity in K562 cells. Phos-tag SDS-PAGE, site-directed mutagenesis (S24A), colony formation assay, mouse survival model, siRNA knockdown Cancer gene therapy Medium 31831854
2020 MLF2 was identified by proteomics as a luminal component of nuclear envelope (NE) blebs formed upon Torsin ATPase manipulation. Using an MLF2-based live-cell imaging platform, NE blebbing was shown to occur rapidly and synchronously immediately after nuclear envelope reformation during mitosis. Bleb formation was independent of ubiquitin conjugation within the bleb but strictly dependent on POM121 (a transmembrane nucleoporin essential for interphase NPC biogenesis). Nup358, a late marker for NPC biogenesis, was underrepresented in Torsin-deficient cells, leading to the conclusion that NE blebs represent aberrant NPC intermediates. Proteomics (mass spectrometry), live-cell fluorescence imaging with MLF2 as reporter, genetic epistasis (POM121 dependence), immunofluorescence, fractionation The Journal of cell biology High 32342107
2023 MLF2 functions as a negative regulator of p53 by interacting with both p53 and USP7 (a deubiquitinase for p53 and MDM2). Via these interactions, MLF2 inhibits USP7 binding to p53 and antagonizes USP7-mediated deubiquitination of p53, thereby promoting p53 destabilization (increased ubiquitination and degradation). MLF2 plays an oncogenic role in colorectal cancer at least partially through this p53-suppression mechanism. Co-immunoprecipitation, ubiquitination assays, MLF2 knockdown/overexpression with p53 stability readouts, colorectal cancer cell line experiments Advanced science (Weinheim, Baden-Wurttemberg, Germany) High 37438558
2024 MLF2 was identified as a chaperone-like protein that regulates a subset of SWI/SNF (BAF) complex target genes by promoting chromatin remodeling activity. In a genome-wide CRISPR KO screen in mouse embryonic stem cells, MLF2 loss impaired SWI/SNF-dependent chromatin remodeling at specific loci, establishing MLF2 as a regulator of SWI/SNF complex activity. Genome-wide CRISPR KO screen with epigenome editing readout, chromatin accessibility assays, gene expression analysis in mouse embryonic stem cells bioRxivpreprint Medium bio_10.1101_2024.06.25.600572
2025 MLF2 was established as a disease-agnostic biomarker and reporter of biomolecular phase transitions (condensate formation). Using MLF2 as a high-content screening readout in an imaging platform, a genome-wide CRISPR/Cas9 screen identified genes linked to primary microcephaly (including ZNF335 and RNF26) that cause proteotoxic condensates. RNF26 deletion provoked nuclear envelope condensates reminiscent of NPC defects, while ZNF335 loss drove nucleoplasmic condensates, establishing a link between aberrant phase transitions and neurodevelopmental disorders. High-content fluorescence imaging using MLF2 as condensate reporter, genome-wide CRISPR/Cas9 screen, machine learning phenotypic clustering, FDA-approved drug screening bioRxivpreprint Medium bio_10.1101_2025.06.07.658469

Source papers

Stage 0 corpus · 49 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2012 Insights into RNA biology from an atlas of mammalian mRNA-binding proteins. Cell 1718 22658674
2002 Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. Proceedings of the National Academy of Sciences of the United States of America 1479 12477932
2010 Network organization of the human autophagy system. Nature 1286 20562859
2015 A human interactome in three quantitative dimensions organized by stoichiometries and abundances. Cell 1015 26496610
2009 A genome-wide RNAi screen identifies multiple synthetic lethal interactions with the Ras oncogene. Cell 843 19490893
2018 VIRMA mediates preferential m6A mRNA methylation in 3'UTR and near stop codon and associates with alternative polyadenylation. Cell discovery 829 29507755
2007 Large-scale mapping of human protein-protein interactions by mass spectrometry. Molecular systems biology 733 17353931
2021 Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. Cell 705 33961781
2011 Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium. Briefings in bioinformatics 656 21873635
2021 Multilevel proteomics reveals host perturbations by SARS-CoV-2 and SARS-CoV. Nature 532 33845483
2004 The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome research 438 15489334
2014 A quantitative chaperone interaction network reveals the architecture of cellular protein homeostasis pathways. Cell 325 25036637
2006 Phosphoproteome analysis of the human mitotic spindle. Proceedings of the National Academy of Sciences of the United States of America 281 16565220
2012 A high-throughput approach for measuring temporal changes in the interactome. Nature methods 273 22863883
2011 A function for cyclin D1 in DNA repair uncovered by protein interactome analyses in human cancers. Nature 269 21654808
2010 Mass spectrometric analysis of lysine ubiquitylation reveals promiscuity at site level. Molecular & cellular proteomics : MCP 262 21139048
2013 The functional interactome landscape of the human histone deacetylase family. Molecular systems biology 235 23752268
2012 MMS19 assembles iron-sulfur proteins required for DNA metabolism and genomic integrity. Science (New York, N.Y.) 230 22678362
2016 A High-Density Map for Navigating the Human Polycomb Complexome. Cell reports 216 27705803
2018 An AP-MS- and BioID-compatible MAC-tag enables comprehensive mapping of protein interactions and subcellular localizations. Nature communications 201 29568061
2015 A deep proteomics perspective on CRM1-mediated nuclear export and nucleocytoplasmic partitioning. eLife 198 26673895
2020 Systems analysis of RhoGEF and RhoGAP regulatory proteins reveals spatially organized RAC1 signalling from integrin adhesions. Nature cell biology 194 32203420
2005 Large-scale analysis of the human ubiquitin-related proteome. Proteomics 154 16196087
2020 A High-Density Human Mitochondrial Proximity Interaction Network. Cell metabolism 148 32877691
2013 Human CIA2A-FAM96A and CIA2B-FAM96B integrate iron homeostasis and maturation of different subsets of cytosolic-nuclear iron-sulfur proteins. Cell metabolism 142 23891004
2019 Mapping the proximity interaction network of the Rho-family GTPases reveals signalling pathways and regulatory mechanisms. Nature cell biology 137 31871319
2017 RNA-binding activity of TRIM25 is mediated by its PRY/SPRY domain and is required for ubiquitination. BMC biology 135 29117863
2022 The ubiquitin-dependent ATPase p97 removes cytotoxic trapped PARP1 from chromatin. Nature cell biology 122 35013556
2016 SPATA2-Mediated Binding of CYLD to HOIP Enables CYLD Recruitment to Signaling Complexes. Cell reports 115 27545878
2007 Toward a confocal subcellular atlas of the human proteome. Molecular & cellular proteomics : MCP 114 18029348
2014 Targeting RPL39 and MLF2 reduces tumor initiation and metastasis in breast cancer by inhibiting nitric oxide synthase signaling. Proceedings of the National Academy of Sciences of the United States of America 94 24876273
2020 Torsin ATPase deficiency leads to defects in nuclear pore biogenesis and sequestration of MLF2. The Journal of cell biology 52 32342107
2016 NTN4 is associated with breast cancer metastasis via regulation of EMT-related biomarkers. Oncology reports 43 27840993
2014 Genetic association signal near NTN4 in Tourette syndrome. Annals of neurology 37 25042818
2014 miR-20a contributes to endometriosis by regulating NTN4 expression. Molecular biology reports 36 24972566
2020 eQTL Colocalization Analyses Identify NTN4 as a Candidate Breast Cancer Risk Gene. American journal of human genetics 32 32871102
1996 cDNA cloning, tissue distribution, and chromosomal localization of myelodysplasia/myeloid leukemia factor 2 (MLF2). Genomics 30 8661158
2019 3'UTR variants of TNS3, PHLDB1, NTN4, and GNG2 genes are associated with IgA nephropathy risk in Chinese Han population. International immunopharmacology 16 30928649
2023 MLF2 Negatively Regulates P53 and Promotes Colorectal Carcinogenesis. Advanced science (Weinheim, Baden-Wurttemberg, Germany) 12 37438558
2024 EXOSC5 maintains cancer stem cell activity in endometrial cancer by regulating the NTN4/integrin β1 signalling axis. International journal of biological sciences 10 38164180
2019 The role of phosphorylation of MLF2 at serine 24 in BCR-ABL leukemogenesis. Cancer gene therapy 8 31831854
2024 CD204-positive M2-like tumor-associated macrophages increase migration of gastric cancer cells by upregulating miR-210 to reduce NTN4 expression. Cancer immunology, immunotherapy : CII 7 38175202
2022 The risk variant rs11836367 contributes to breast cancer onset and metastasis by attenuating Wnt signaling via regulating NTN4 expression. Science advances 6 35687692
2016 Investigation of SNP rs2060546 Immediately Upstream to NTN4 in a Danish Gilles de la Tourette Syndrome Cohort. Frontiers in neuroscience 5 27920664
2025 Association Between Synovial NTN4 Expression and Pain Scores, and Its Effects on Fibroblasts and Sensory Neurons in End-Stage Knee Osteoarthritis. Cells 4 40136644
2021 The Interaction of NTN4 and miR-17-92 Polymorphisms on Breast Cancer Susceptibility in a Chinese Population. Clinical breast cancer 4 35232666
2023 Hepatic Expression of NTN4 and Its Receptors in Patients with Hepatocellular Carcinoma. Asian Pacific journal of cancer prevention : APJCP 3 38156865
2011 Identification of parental line specific effects of MLF2 on resistance to coccidiosis in chickens. BMC proceedings 1 21645301
2025 Elevation of NTN4 Expression and Its Possible Regulation by Tumor Necrosis Factor-Alpha (TNF-α) in a Rat Model of Rotator Cuff Tear. Cureus 0 40688916