Affinage

GMEB2

Glucocorticoid modulatory element-binding protein 2 · UniProt Q9UKD1

Length
530 aa
Mass
56.4 kDa
Annotated
2026-06-10
17 papers in source corpus 9 papers cited in narrative 9 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 4/5 claims corpus-supported (80%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

GMEB2 is a nuclear DNA-binding transcription factor that modulates steroid hormone receptor transactivation by acting at the glucocorticoid modulatory element (GME), a regulatory site functioning in a pathway parallel to and distinct from the canonical GRE fold-induction pathway (PMID:9651376, PMID:10854715). GMEB2 binds GME DNA and forms a heteromeric complex with GMEB1, with DNA binding markedly enhanced upon co-assembly of the two proteins (PMID:9651376); this DNA recognition is mediated by a SAND domain that is necessary and sufficient for GME binding and presents a conserved KDWK motif on an alpha-helical surface, with an associated zinc-binding motif shaping the domain's C-terminal conformation (PMID:12702733). Functionally, GMEB2 possesses intrinsic transactivation activity and interacts directly with the glucocorticoid receptor (GR) and with the coactivator CBP, and its overexpression shifts the GR agonist dose-response curve rightward and decreases antisteroid partial agonist activity in a manner consistent with squelching of limiting cofactors (PMID:10894151). This modulatory activity extends to the progesterone receptor, where GMEB2 differentially alters EC50, partial agonist activity, and Vmax, establishing it as a general modulator of steroid receptor pharmacology rather than a GR-specific factor (PMID:18215457). Beyond hormone signaling, GMEB2 transactivates the ADRM1 promoter to drive NF-κB nuclear translocation and promote colorectal cancer cell growth, and its protein level is post-transcriptionally controlled by the m6A reader YTHDF1, which binds and stabilizes GMEB2 mRNA (PMID:36551532).

Mechanistic history

Synthesis pass · year-by-year structured walk · 9 steps
  1. 1998 High

    Established GMEB2 as a sequence-specific DNA-binding protein and revealed that its GME binding is potentiated by heteromeric assembly with GMEB1, defining the molecular basis of the GME-binding complex.

    Evidence RACE cloning, in vitro transcription/translation, and gel shift/supershift assays demonstrating GME binding and GMEB1/GMEB2 heteromer formation

    PMID:9651376

    Open questions at the time
    • DNA-binding domain not yet mapped at this stage
    • no functional consequence for transcription demonstrated yet
    • endogenous complex stoichiometry not resolved
  2. 2000 High

    Determined that GMEB2 modulates GR transactivation by interacting with GR and CBP and shifting the agonist dose-response curve, identifying cofactor squelching as the likely mechanism.

    Evidence Mammalian one- and two-hybrid assays, GST pull-down, HAT assays, and transient-transfection reporter assays

    PMID:10894151

    Open questions at the time
    • GMEB2 has no intrinsic HAT activity, leaving the coactivator link indirect
    • identity of the squelched limiting cofactors not defined
    • interactions shown in heterologous assays, not at endogenous loci
  3. 2000 Medium

    Placed GME-mediated modulation in a regulatory pathway parallel to, and not overlapping with, the canonical GRE fold-induction pathway, clarifying where GMEB activity acts.

    Evidence Reporter constructs varying GME position/phasing/sequence, CREB overexpression, and gel shift for GR binding

    PMID:10854715

    Open questions at the time
    • no biochemical reconstitution of the GME pathway
    • molecular mechanism distinguishing the two pathways not resolved
    • position-dependence basis unexplained
  4. 2000 Medium

    Showed GMEB1 and GMEB2 derive from a common ancestral gene with conserved genomic structure and are enriched in fetal/developing tissues, hinting at a developmental role.

    Evidence Genomic sequencing, chromosomal mapping, Northern tissue distribution, and promoter-reporter transfection

    PMID:10734202

    Open questions at the time
    • developmental function not functionally tested
    • tissue expression descriptive only
    • regulation of GMEB2 transcription not characterized
  5. 2003 High

    Provided atomic-resolution definition of the SAND domain as the GME DNA-recognition module, with the KDWK motif on the binding surface and a zinc motif shaping domain conformation; GMEB2's SAND is 80% identical, extending the model to GMEB2.

    Evidence X-ray crystallography (1.55 Å) and NMR of GMEB1 SAND, binding assays, and site-directed mutagenesis

    PMID:12702733

    Open questions at the time
    • GMEB2 SAND structure inferred from GMEB1, not directly solved
    • structural basis of heteromerization not addressed
    • DNA-bound complex structure not determined
  6. 2004 Medium

    Mapped GMEB2 functional architecture, showing that oligomerization, GR/CBP binding, DNA binding, and receptor modulation each require large protein regions while only transactivation localizes to a discrete region, and that GMEB2/GMEB1 differences are quantitative.

    Evidence Deletion mutagenesis with two-hybrid, pull-down, and reporter assays

    PMID:14705952

    Open questions at the time
    • no high-resolution structure of full-length GMEB2
    • distributed functional regions preclude clean domain assignment
    • basis of quantitative GMEB1/GMEB2 functional differences not identified
  7. 2007 Medium

    Demonstrated GMEB2 modulates progesterone receptor as well as glucocorticoid receptor, broadening its role to general steroid-receptor pharmacology.

    Evidence Parallel PR and GR transient-transfection reporter dose-response assays

    PMID:18215457

    Open questions at the time
    • tested only in reporter systems
    • endogenous PR target genes not examined
    • mechanism of differential receptor modulation unresolved
  8. 2011 Medium

    Connected GMEB proteins to IL-12/PI3K/Akt-driven T cell survival, indicating GMEB-mediated dampening of glucocorticoid receptor apoptotic gene induction.

    Evidence siRNA knockdown of GMEB1 in human T cells, apoptosis flow cytometry, and PI3K inhibition; IL-12 induction of GMEB1/GMEB2

    PMID:21840619

    Open questions at the time
    • functional knockdown performed on GMEB1, not GMEB2 directly
    • GMEB2 measured only at the induction level
    • target apoptotic genes not identified
  9. 2022 Medium

    Revealed a GMEB2 oncogenic axis in which GMEB2 transactivates ADRM1 to activate NF-κB and drive colorectal cancer growth, and is itself stabilized post-transcriptionally by the m6A reader YTHDF1.

    Evidence GMEB2 knockdown, ADRM1 luciferase promoter assay, ADRM1 rescue, NF-κB translocation assay, YTHDF1 RIP, and xenograft model

    PMID:36551532

    Open questions at the time
    • direct GMEB2 binding to the ADRM1 promoter (e.g., ChIP) not detailed
    • relationship between this NF-κB role and steroid-receptor modulation unclear
    • single-lab study in one cancer context

Open questions

Synthesis pass · forward-looking unresolved questions
  • How GMEB2 integrates its steroid-receptor modulatory function with its NF-κB-activating oncogenic role, and what determines its target-gene selectivity in each context, remains unresolved.
  • no unified model linking GME-based receptor modulation and ADRM1/NF-κB activation
  • genome-wide GMEB2 binding sites not defined
  • physiological roles in development and immunity not directly tested for GMEB2

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0003677 DNA binding 2 GO:0098772 molecular function regulator activity 2 GO:0140110 transcription regulator activity 2
Localization
GO:0005634 nucleus 2
Pathway
R-HSA-162582 Signal Transduction 2 R-HSA-74160 Gene expression (Transcription) 2
Partners
CBPGMEB1GRYTHDF1
Complex memberships
GMEB1/GMEB2 GME-binding heteromeric complex

Evidence

Reading pass · 9 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1998 GMEB-2 (67-kDa protein) was cloned and shown to bind GME DNA in gel shift assays; binding to GME DNA increased markedly after mixing with GMEB-1, forming a heteromeric complex similar to that derived from HTC cell cytosol. GMEB-2 shares a unique KDWKR domain with proteins from diverse organisms, placing it in a novel family of transcription factors. PCR of degenerate oligonucleotides, 5'- and 3'-RACE cloning, in vitro transcription/translation, gel shift assays, antibody supershift The Journal of biological chemistry High 9651376
2000 GMEB-1 and GMEB-2 each possess intrinsic transactivation activity in mammalian one-hybrid assays. Both proteins interact with glucocorticoid receptor (GR) in mammalian two-hybrid and pull-down assays. Both proteins also interact with CREB-binding protein (CBP) in two-hybrid assays. Neither protein has histone acetyltransferase (HAT) activity. Overexpression of either or both GMEBs causes a reversible right shift in the GR dose-response curve and decreased partial agonist activity of antisteroids, consistent with squelching of limiting cofactors. Mammalian one-hybrid assay, mammalian two-hybrid assay, GST pull-down assay, HAT activity assay, transient transfection with reporter gene Molecular endocrinology (Baltimore, Md.) High 10894151
2000 GME activity requires an optimal position within 250 bp upstream of a tandem GRE driving a complex promoter. GMEB-1 and GMEB-2 mediate GME-dependent modulation of GR transcriptional properties via a pathway parallel to (not overlapping with) the GRE fold-induction pathway. Overexpression of CREB reduced GRE but not GME activity, and no effect of the GME was observed on GR binding to a single GRE. Transient transfection with reporter gene constructs varying GME position, phasing, and sequence; CREB overexpression; gel shift for GR binding Molecular and cellular endocrinology Medium 10854715
2000 Human GMEB-1 and rat GMEB-2 are encoded by distinct genes on chromosomes 1 and 20, respectively, but share highly conserved genomic structure including intron organization, indicating evolution from a single parent gene. Both genes are most highly expressed in fetal and developing tissues. Both possess promoter regions with high transcriptional activity in transiently transfected cells. Genomic sequencing, chromosomal mapping, Northern blot/tissue distribution analysis, promoter-reporter transfection Nucleic acids research Medium 10734202
2003 Crystal structure of the GMEB-1 SAND domain at 1.55 Å resolution was determined. The SAND domain is necessary and sufficient for binding to GME DNA. NMR and binding studies mapped the DNA recognition surface to an alpha-helical region exposing the conserved KDWK motif. Site-directed mutagenesis identified key residues for DNA binding. The GMEB1 SAND domain contains a zinc-binding motif not present in Sp100b SAND; zinc is not required for DNA binding but determines the C-terminal conformation of the domain. The GMEB2 SAND domain shares 80% sequence identity with GMEB1 SAND domain. X-ray crystallography (1.55 Å), NMR spectroscopy, binding assays, site-directed mutagenesis Molecular endocrinology (Baltimore, Md.) High 12702733
2004 Structure/activity analysis of GMEB-2 showed that homo- and hetero-oligomerization, binding to GR, binding to CBP, DNA binding, and modulation of GR transcriptional properties (dose-response curve position and partial agonist activity) each require large regions of GMEB-2. Only intrinsic transactivation activity could be localized to a small region. Domain organization of GMEB-2 is extremely similar to GMEB-1, with quantitative differences in activity arising from amino acid sequence variation rather than global structural differences. Deletion mutagenesis of GMEB-2 constructs; mammalian two-hybrid assay; pull-down assay; transient transfection reporter assay Biochemistry Medium 14705952
2007 GMEB-2 can differentially modulate progesterone receptor (PR) versus glucocorticoid receptor (GR) induction parameters (EC50, partial agonist activity, Vmax) under otherwise identical conditions, demonstrating that GMEB-2's modulatory activity is not restricted to GR. Transient transfection reporter assays with PR and GR in parallel; comparison of dose-response curves Molecular and cellular endocrinology Medium 18215457
2011 siRNA knockdown of GMEB1 reversed the protective effect of IL-12 on dexamethasone-induced T cell apoptosis, placing GMEB1 (which interacts with GMEB2 as part of the GME binding complex) downstream of IL-12/PI3K/Akt signaling in T cell survival. IL-12 induced both GMEB1 and GMEB2 expression. This suggests GMEB proteins reduce transactivation of glucocorticoid receptor-mediated apoptotic gene induction. siRNA knockdown of GMEB1 in human T cells; flow cytometry for apoptosis; PI3K inhibitor treatment Immunobiology Medium 21840619
2022 GMEB2 acts as a transcription factor that directly transactivates the ADRM1 promoter, increasing ADRM1 expression. The GMEB2/ADRM1 axis induces nuclear translocation of NF-κB, activating NF-κB signaling. GMEB2 knockdown inhibited colorectal cancer cell growth in vitro and in vivo. YTHDF1 (an m6A reader) recognizes and binds m6A sites on GMEB2 mRNA, enhancing its stability and thereby upregulating GMEB2 protein levels. GMEB2 knockdown (siRNA/shRNA), luciferase promoter assay for ADRM1, rescue experiments with ADRM1, NF-κB nuclear translocation assay, RIP (RNA immunoprecipitation) for YTHDF1-GMEB2 mRNA interaction, xenograft tumor model Cancers Medium 36551532

Source papers

Stage 0 corpus · 17 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2000 Properties of the glucocorticoid modulatory element binding proteins GMEB-1 and -2: potential new modifiers of glucocorticoid receptor transactivation and members of the family of KDWK proteins. Molecular endocrinology (Baltimore, Md.) 44 10894151
2003 Crystal structure and nuclear magnetic resonance analyses of the SAND domain from glucocorticoid modulatory element binding protein-1 reveals deoxyribonucleic acid and zinc binding regions. Molecular endocrinology (Baltimore, Md.) 39 12702733
1998 Cloning and characterization of a novel binding factor (GMEB-2) of the glucocorticoid modulatory element. The Journal of biological chemistry 34 9651376
2020 Adult diffuse glioma GWAS by molecular subtype identifies variants in D2HGDH and FAM20C. Neuro-oncology 32 32386320
2014 Both genes and lncRNAs can be used as biomarkers of prostate cancer by using high throughput sequencing data. European review for medical and pharmacological sciences 28 25491628
2019 Glucocorticoid modulatory element-binding protein 1 (GMEB1) interacts with the de-ubiquitinase USP40 to stabilize CFLARL and inhibit apoptosis in human non-small cell lung cancer cells. Journal of experimental & clinical cancer research : CR 27 31046799
2000 Ability of the glucocorticoid modulatory element to modify glucocorticoid receptor transactivation indicates parallel pathways for the expression of glucocorticoid modulatory element and glucocorticoid response element activities. Molecular and cellular endocrinology 27 10854715
1999 Cloning and characterization of hGMEB1, a novel glucocorticoid modulatory element binding protein. FEBS letters 22 10386584
2000 Genomic organization of human GMEB-1 and rat GMEB-2: structural conservation of two multifunctional proteins. Nucleic acids research 18 10734202
2011 IL-12 inhibits glucocorticoid-induced T cell apoptosis by inducing GMEB1 and activating PI3K/Akt pathway. Immunobiology 17 21840619
2007 Differential modulation of glucocorticoid and progesterone receptor transactivation. Molecular and cellular endocrinology 15 18215457
2000 Cloning of a mouse glucocorticoid modulatory element binding protein, a new member of the KDWK family. FEBS letters 15 10692587
2020 A functional variant on 20q13.33 related to glioma risk alters enhancer activity and modulates expression of multiple genes. Human mutation 14 33169458
2022 GMEB2 Promotes the Growth of Colorectal Cancer by Activating ADRM1 Transcription and NF-κB Signalling and Is Positively Regulated by the m6A Reader YTHDF1. Cancers 11 36551532
2004 Structure/activity relationships for GMEB-2: the second member of the glucocorticoid modulatory element-binding complex. Biochemistry 7 14705952
2018 From Matrices to Knowledge: Using Semantic Networks to Annotate the Connectome. Frontiers in neuroanatomy 2 30581382
2025 Prediction of vaginal birth after induction of labor with maternal circulating RNA transcripts. American journal of obstetrics and gynecology 0 40523495

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