Affinage

SMARCD2

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 2 · UniProt Q92925

Length
531 aa
Mass
58.9 kDa
Annotated
2026-06-10
17 papers in source corpus 7 papers cited in narrative 8 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 5/5 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SMARCD2 (BAF60b) is a context-specific subunit of SWI/SNF (BAF) chromatin-remodeling complexes that bridges lineage-specifying transcription factors to chromatin to direct cell-type-specific gene programs (PMID:28369036, PMID:28369034). In granulopoiesis it physically interacts with CEBPɛ and is required for CEBPɛ recruitment to the promoters of neutrophil secondary granule genes, and loss-of-function mutations in patients with specific granule deficiency abolish the SMARCD2–SWI/SNF interaction and secondary granule gene expression (PMID:28369036, PMID:28369034). This developmental role extends to early myeloid-erythroid progenitor differentiation (PMID:28369034, PMID:28369036), to leukaemic self-renewal in MLL-rearranged leukaemia where SMARCD2 regulates haematopoietic stem cell-associated genes (PMID:26571505), to RUNX1-dependent CCR9 expression governing regulatory T cell migration and inflammation (PMID:38996070), and to a C/EBPβ-dependent program in liver that suppresses Pparγ and limits hepatic lipid accumulation (PMID:39046829). Its functional specificity—which cannot be supplied by the 63%-identical paralog SMARCD1—is encoded by its divergent coiled-coil 1 and SWIB domains (PMID:28369034). SMARCD2 also couples chromatin opening to ATM–p53 activation independently of DNA damage during attempted lineage conversion (PMID:28303890), and its protein levels are controlled by Rac-GTPase-dependent, Unkempt-mediated degradative ubiquitination in the nucleus (PMID:20148946).

Mechanistic history

Synthesis pass · year-by-year structured walk · 7 steps
  1. 2010 Medium

    Established the first regulatory input on SMARCD2 abundance, showing its levels are controlled post-translationally rather than only transcriptionally.

    Evidence Yeast two-hybrid, Co-IP, ubiquitination assay, and MG132 rescue in mammalian cells linking BAF60b to Unkempt-mediated, Rac-dependent ubiquitination

    PMID:20148946

    Open questions at the time
    • Single lab; the physiological signals that trigger Rac/Unkempt-dependent turnover are not defined
    • Does not connect degradation to a specific chromatin-remodeling output
  2. 2015 Medium

    Showed SMARCD2 is a selective dependency in a malignant context, distinguishing its requirement from general SWI/SNF housekeeping function.

    Evidence shRNA knockdown with RNA-seq and in vitro/in vivo leukaemia expansion assays in MLL-rearranged leukaemia

    PMID:26571505

    Open questions at the time
    • Human cells did not reproduce the mouse c-MYC dependency, leaving species-specific target programs unresolved
    • Direct transcription-factor partners in leukaemia not identified
  3. 2017 High

    Defined the core molecular mechanism: SMARCD2 within SWI/SNF recruits CEBPɛ to drive a specific gene program, and human disease mutations validate this axis.

    Evidence Co-IP, in vitro interaction, ChIP at secondary granule promoters, Smarcd2-deficient mouse, and patient mutation analysis (two independent papers)

    PMID:28369034 PMID:28369036

    Open questions at the time
    • Structure of the SMARCD2–CEBPɛ interface not resolved
    • Whether the same recruitment logic generalizes to other transcription factors was not tested here
  4. 2017 Medium

    Explained the basis of paralog non-redundancy, attributing SMARCD2's unique granulopoietic function to specific protein domains.

    Evidence Domain-swap and SMARCD1-substitution rescue experiments in Smarcd2-deficient cells

    PMID:28369034

    Open questions at the time
    • Single lab; the binding partner(s) discriminated by the coiled-coil 1/SWIB domains not mapped biochemically
    • Domain contributions in non-myeloid contexts untested
  5. 2017 Medium

    Revealed a chromatin-to-signalling link, showing SMARCD2-driven chromatin opening can activate ATM-p53 to enforce cell identity.

    Evidence ChIP and ATM recruitment assays with knockdown in a fibroblast-to-hepatocyte conversion model

    PMID:28303890

    Open questions at the time
    • Mechanism by which open chromatin recruits ATM independent of DNA damage not defined
    • Single lab and a specialized lineage-conversion system
  6. 2024 Medium

    Extended the transcription-factor-recruitment paradigm to immune regulation via RUNX1, linking SMARCD2 to Treg trafficking.

    Evidence Reciprocal Co-IP, ATAC-seq, transcriptome analysis, and conditional knockout mice in EAE and colitis models

    PMID:38996070

    Open questions at the time
    • Direct genomic co-occupancy of SMARCD2 and RUNX1 at the CCR9 locus not shown by ChIP
    • Single lab
  7. 2024 Medium

    Generalized SMARCD2's TF-partnering role to metabolism, showing a C/EBPβ-dependent repression of Pparγ that constrains hepatic steatosis.

    Evidence Co-IP, ATAC-seq motif analysis, and liver-specific knockout/transgenic mouse models

    PMID:39046829

    Open questions at the time
    • Whether C/EBPβ recruitment depends on the same domains as CEBPɛ recruitment untested
    • Single lab

Open questions

Synthesis pass · forward-looking unresolved questions
  • How a single SWI/SNF subunit selects among distinct transcription-factor partners (CEBPɛ, RUNX1, C/EBPβ) across tissues remains unresolved at structural and biochemical resolution.
  • No structural model of any SMARCD2–transcription-factor interface
  • Rules linking domain identity to partner choice not established
  • Genome-wide direct SMARCD2 occupancy maps lacking

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 4 GO:0140110 transcription regulator activity 4
Localization
GO:0005634 nucleus 1
Pathway
R-HSA-74160 Gene expression (Transcription) 4 R-HSA-1266738 Developmental Biology 2 R-HSA-4839726 Chromatin organization 2
Partners
CEBPBCEBPERUNX1UNK
Complex memberships
SWI/SNF (BAF)

Evidence

Reading pass · 8 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2017 SMARCD2 directly interacts with the transcription factor CEBPɛ and controls expression of neutrophil proteins stored in specific granules; loss-of-function mutations in SMARCD2 identified in patients with specific granule deficiency abolish this interaction with SWI/SNF and thereby secondary granule gene expression. Co-immunoprecipitation, in vitro interaction assays, chromatin immunoprecipitation, patient mutation analysis Nature genetics High 28369034 28369036
2017 SMARCD2-containing SWI/SNF complexes are required for CEBPɛ transcription factor recruitment to the promoter of neutrophilic secondary granule genes during granulocyte differentiation; SMARCD2 controls early steps in differentiation of myeloid-erythroid progenitor cells. Smarcd2-deficient mouse model, chromatin immunoprecipitation (ChIP) at secondary granule gene promoters, gene expression profiling Nature genetics High 28369034 28369036
2017 The functional specificity of SMARCD2 in granulocyte development (which cannot be replaced by the 63%-identical paralog SMARCD1) is conferred by its divergent coiled-coil 1 and SWIB domains. Domain swap experiments, Smarcd2-deficient mouse rescue assays with SMARCD1 substitution Nature genetics Medium 28369034
2010 BAF60b (SMARCD2) is ubiquitinated through a Rac GTPase-dependent signalling process mediated by the mammalian RING finger protein Unkempt, which binds BAF60b and promotes its degradative ubiquitination; this process occurs in the nuclear compartment. Two-hybrid cloning, Co-immunoprecipitation, ubiquitination assay, proteasome inhibitor (MG132) treatment, immunofluorescence The FEBS journal Medium 20148946
2017 Baf60b (SMARCD2) links chromatin opening to ATM activation during lineage conversion by facilitating ATM recruitment to open chromatin regions at hepatic gene loci, activating the ATM-p53 pathway independently of DNA damage to block cell identity conversion. Chromatin immunoprecipitation, ATM recruitment assay, loss-of-function knockdown in fibroblast-to-hepatocyte conversion model Cell research Medium 28303890
2015 SMARCD2 is selectively required for leukaemic cell expansion and self-renewal in MLL-rearranged leukaemia, where it regulates expression of haematopoietic stem cell-associated genes; however, unlike mouse data, it is not required for c-MYC-regulated gene expression in human cells. shRNA knockdown, gene expression profiling (RNA-seq), in vitro and in vivo leukaemia expansion assays PloS one Medium 26571505
2024 BAF60b (SMARCD2) interacts with transcription factor RUNX1 to promote CCR9 expression on regulatory T cells, facilitating their migration to inflammatory tissues and suppressing inflammation in EAE and colitis models. Co-immunoprecipitation, transcriptome analysis, ATAC-seq (genome-wide chromatin landscape), conditional knockout mouse models Cell reports Medium 38996070
2024 Hepatic BAF60b (SMARCD2) interacts with transcription factor C/EBPβ to suppress Pparγ gene expression, thereby controlling hepatic lipid accumulation; BAF60b deficiency promotes HFD-induced liver steatosis while transgenic overexpression attenuates NAFLD. Co-immunoprecipitation, ATAC-seq motif analysis, liver-specific knockout and transgenic mouse models, gene expression analysis Diabetes Medium 39046829

Source papers

Stage 0 corpus · 17 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2017 Chromatin-remodeling factor SMARCD2 regulates transcriptional networks controlling differentiation of neutrophil granulocytes. Nature genetics 84 28369036
2017 SMARCD2 subunit of SWI/SNF chromatin-remodeling complexes mediates granulopoiesis through a CEBPɛ dependent mechanism. Nature genetics 63 28369034
2015 SWI/SNF Subunits SMARCA4, SMARCD2 and DPF2 Collaborate in MLL-Rearranged Leukaemia Maintenance. PloS one 23 26571505
2017 Baf60b-mediated ATM-p53 activation blocks cell identity conversion by sensing chromatin opening. Cell research 21 28303890
2010 The SWI/SNF protein BAF60b is ubiquitinated through a signalling process involving Rac GTPase and the RING finger protein Unkempt. The FEBS journal 21 20148946
1997 Gene structure of rat BAF60b, a component of mammalian SW1/SNF complexes, and its physical linkage to the growth hormone gene and transcription factor SUG/proteasome p45 gene. Gene 12 9427560
2020 Defective neutrophil development and specific granule deficiency caused by a homozygous splice-site mutation in SMARCD2. The Journal of allergy and clinical immunology 11 33279574
2020 Novel Frameshift Autosomal Recessive Loss-of-Function Mutation in SMARCD2 Encoding a Chromatin Remodeling Factor Mediates Granulopoiesis. Journal of clinical immunology 10 33025377
2017 A SMARCD2-containing mSWI/SNF complex is required for granulopoiesis. Nature genetics 10 28442792
1999 Gene structure of rat testicular cell adhesion molecule 1 (TCAM-1), and its physical linkage to genes coding for the growth hormone and BAF60b, a component of SWI/SNF complexes. Gene 10 9889334
2024 SWI/SNF chromatin remodeling factor BAF60b restrains inflammatory diseases by affecting regulatory T cell migration. Cell reports 9 38996070
2024 Identification of BAF60b as a Chromatin-Remodeling Checkpoint of Diet-Induced Fatty Liver Disease. Diabetes 5 39046829
2023 Clinical and transcriptomic characteristics of a novel SMARCD2 mutation that disrupts neutrophil maturation and function. Pediatric blood & cancer 5 37712719
1999 Evidence for evolutionary conservation of a physical linkage between the human BAF60b, a subunit of SWI/SNF complex, and thyroid hormone receptor interacting protein-1 genes on chromosome 17. Genome 5 10382302
2022 Specific Granule Deficiency Due To Novel Homozygote SMARCD2 Variant. Pediatric allergy, immunology, and pulmonology 3 35320004
2022 Congenital Neutropenia with Specific Granulocyte Deficiency Caused by Novel Double Heterozygous SMARCD2 Mutations. Hematology reports 2 36135322
2025 Novel Nonsense Mutation in SMARCD2 Gene Results in Dysplasia of All Myeloid Cell Lines. EJHaem 0 41321749

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