Affinage

SH2B2

SH2B adapter protein 2 · UniProt O14492

Length
632 aa
Mass
67.7 kDa
Annotated
2026-06-10
23 papers in source corpus 9 papers cited in narrative 9 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 5/6 claims corpus-supported (83%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SH2B2 (APS) is a cytoplasmic adaptor protein that couples activated receptor and non-receptor tyrosine kinases to downstream signaling through its modular domain architecture: N-terminal dimerization domains mediate homo- and heterodimerization with SH2B1, and an SH2 domain docks onto tyrosyl-phosphorylated targets including JAK2, the insulin and IGF-1 receptors, and IRS-1/IRS-2 (PMID:25126397). Structurally, the SH2 domain engages two phosphotyrosines in the insulin receptor activation loop via a dimeric interaction, providing a high-avidity docking platform on the activated receptor (PMID:23457259). An alternatively spliced isoform, SH2B2beta, lacks the SH2 domain and functions as an endogenous dominant-negative inhibitor by heterodimerizing through its dimerization domain with SH2B1 and SH2B2alpha, thereby attenuating SH2B1-promoted JAK2 activation, IRS-1 phosphorylation, and insulin signaling (PMID:17204555). Despite this role in insulin-receptor signaling, SH2B2 is dispensable for systemic energy and glucose homeostasis, with knockout mice metabolically normal (PMID:25126397), but it acts together with SH2B1 in the liver to regulate triglyceride synthesis, lipolysis, and VLDL secretion (PMID:24358267). Beyond metabolism, SH2B2 promotes survival of germinal center B cells and IgE+ plasma cells downstream of BCR signaling (PMID:39090233), enhances NGF-induced neuronal differentiation via TrkA (PMID:22028877), and exerts neuroprotective, anti-apoptotic effects in dopaminergic neurons in models of Parkinsonian injury (PMID:41482210). Unlike SH2B1, SH2B2 does not undergo nucleocytoplasmic shuttling (PMID:19372237).

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 2007 High

    Established that a splice isoform of SH2B2 acts as a built-in negative regulator of the SH2B adaptor family, defining an intrinsic brake on JAK2 and insulin signaling.

    Evidence GST pulldown, reciprocal co-IP, and functional kinase/phosphorylation assays in cells

    PMID:17204555

    Open questions at the time
    • Physiological contexts where the beta isoform predominates were not defined
    • Quantitative stoichiometry of heterodimers in vivo not established
  2. 2009 Medium

    Distinguished SH2B2 from its paralog SH2B1 by showing it lacks nucleocytoplasmic shuttling, constraining where SH2B2 can act in the cell.

    Evidence Live imaging and subcellular localization comparison of SH2B family members

    PMID:19372237

    Open questions at the time
    • Functional consequence of restricted localization not tested
    • No mapping of the determinants that distinguish the two paralogs
  3. 2011 Medium

    Placed SH2B2 in neurotrophin signaling by showing it enhances NGF-induced differentiation through TrkA, with SH2B3 acting as a competitive antagonist for receptor binding.

    Evidence Overexpression, co-IP of TrkA binding, and neurite outgrowth assays in PC12 cells

    PMID:22028877

    Open questions at the time
    • Endogenous requirement for SH2B2 in neuronal differentiation not tested by loss-of-function
    • Downstream effectors of SH2B2-TrkA coupling unresolved
  4. 2013 Medium

    Defined the structural basis of SH2B2 recruitment, showing its dimeric SH2 domain engages two phosphotyrosines in the insulin receptor activation loop.

    Evidence Structural and biochemical characterization synthesized in review

    PMID:23457259

    Open questions at the time
    • Affinity and selectivity for distinct receptor phosphosites not quantified in this corpus
    • Functional output of activation-loop docking not directly linked
  5. 2013 Medium

    Demonstrated a non-redundant hepatic role: SH2B2 acts with SH2B1 to control triglyceride synthesis, lipolysis, and VLDL secretion, dissociating this lipid function from insulin/glucose control.

    Evidence Hepatocyte-specific SH2B1 knockout combined with whole-body SH2B2 knockout mice with metabolic phenotyping and gene expression analysis

    PMID:24358267

    Open questions at the time
    • Direct molecular link between SH2B2 and DGAT2/ATGL regulation not established
    • SH2B2-specific contribution distinct from SH2B1 not isolated
  6. 2014 Medium

    Consolidated SH2B2 domain function and binding partners while establishing that, unlike SH2B1, SH2B2 is dispensable for systemic energy and glucose homeostasis.

    Evidence Knockout mouse phenotyping and biochemical binding assays synthesized from prior work

    PMID:25126397

    Open questions at the time
    • Compensation by paralogs in knockout mice not excluded
    • Tissue-specific requirements masked by whole-body phenotyping
  7. 2024 Medium

    Revealed an immune role for SH2B2 as a survival factor for germinal center B cells and IgE+ plasma cells downstream of BCR signaling.

    Evidence Aps-deficient mice with in vivo immunization, flow cytometry for GC B cell frequency/apoptosis, and in vitro BCR crosslinking

    PMID:39090233

    Open questions at the time
    • Molecular pathway by which SH2B2 promotes B cell survival not defined
    • Direct phosphotyrosine partners in BCR signaling not identified
  8. 2025 Medium

    Identified a neuroprotective, anti-apoptotic function for SH2B2 in dopaminergic neurons under Parkinsonian insult.

    Evidence MPTP mouse and MPP+-treated SH-SY5Y models with SH2B2 overexpression rescue, behavioral, viability, apoptosis, and marker readouts

    PMID:41482210

    Open questions at the time
    • Mechanism connecting SH2B2 to TH and neuroinflammation markers not resolved
    • Endogenous loss-of-function effect in dopaminergic neurons not tested
    • Single lab

Open questions

Synthesis pass · forward-looking unresolved questions
  • How SH2B2's adaptor activity at specific receptors is mechanistically translated into its divergent tissue roles (B cell survival, neuronal protection, hepatic lipid handling) remains unresolved.
  • No unifying downstream effector connecting receptor docking to cell-type-specific outcomes
  • Roles of dimerization with SH2B1 in non-metabolic tissues not tested
  • No structural data on full-length SH2B2 in this corpus

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 2 GO:0098772 molecular function regulator activity 1
Localization
GO:0005829 cytosol 1
Pathway
R-HSA-162582 Signal Transduction 3 R-HSA-1430728 Metabolism 1 R-HSA-168256 Immune System 1

Evidence

Reading pass · 9 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2007 SH2B2beta, a splice isoform of SH2B2 lacking an SH2 domain, binds to SH2B1 and SH2B2alpha via its dimerization (DD) domain (demonstrated by GST pulldown in vitro and co-immunoprecipitation in intact cells), and markedly attenuates SH2B1-promoted JAK2 activation and subsequent IRS-1 tyrosine phosphorylation, as well as SH2B1- or SH2B2alpha-promoted insulin signaling, acting as an endogenous inhibitor. GST fusion protein pulldown (in vitro), co-immunoprecipitation in intact cells, functional kinase/phosphorylation assays Endocrinology High 17204555
2013 Deletion of liver SH2B1 in SH2B2 null mice attenuated VLDL secretion, and adult-onset deletion of hepatic SH2B1 (alone) decreased DGAT2 expression and increased ATGL expression, indicating that SH2B1 and SH2B2 together regulate hepatic triglyceride synthesis, lipolysis, and VLDL secretion without affecting insulin sensitivity or glucose metabolism. Hepatocyte-specific SH2B1 knockout combined with whole-body SH2B2 knockout mice; metabolic phenotyping, gene expression analysis (qRT-PCR/Western blot) PloS one Medium 24358267
2021 SH2B2 participates in insulin receptor signaling by being phosphorylated downstream of the activated insulin receptor, initiating activation of G proteins such as TC10 (via the c-Cbl/CAP/TC10 pathway). Review synthesizing prior experimental work on insulin receptor signaling pathways The Journal of clinical investigation Low 33393497
2013 The SH2 domain of SH2B2 (APS) binds to phosphorylated tyrosines in the insulin receptor activation loop (engaging two phosphotyrosines via a dimeric SH2 domain interaction), providing a docking site for this adaptor protein. Structural and biochemical characterization reviewed; dimeric SH2 domain engagement of two phosphotyrosines in activation loop described from prior structural studies Cold Spring Harbor perspectives in biology Medium 23457259
2014 SH2B2 (APS) forms homo- or heterodimers with SH2B1 via N-terminal dimerization domains; its SH2 domain binds tyrosyl-phosphorylated proteins including JAK2, insulin receptors, IGF-1 receptors, IRS-1, and IRS-2. Unlike SH2B1, SH2B2 is not required for maintenance of normal energy and glucose homeostasis (SH2B2 knockout mice are metabolically normal). Genetic knockout mouse studies; biochemical binding assays (co-IP, domain analysis) synthesized from prior work World journal of diabetes Medium 25126397
2011 SH2B2 (APS) enhances NGF-induced neuronal differentiation in PC12 cells; SH2B3 competes with SH2B2 for TrkA binding to inhibit this effect, as overexpression of the SH2 domain of SH2B3 reduces SH2B1β-TrkA interaction and inhibits NGF-induced neurite outgrowth. Overexpression studies in PC12 cells, co-immunoprecipitation of TrkA binding, neurite outgrowth assays PloS one Medium 22028877
2009 Nuclear translocation of SH2B2 (APS) was not observed, in contrast to SH2B1β which shuttles between plasma membrane and nucleus; SH2B2 lacks nuclear localization/export signal-dependent nucleocytoplasmic shuttling function. Live imaging and localization studies of SH2B family members in cells; comparison of SH2B1β and SH2B2 subcellular localization Molecular endocrinology Medium 19372237
2024 In Aps/Sh2b2-deficient mice, GC B cell numbers are reduced after immunization and cell death of Aps−/− GC B cells is enhanced compared to wild-type. IgE-specific production is impaired. Furthermore, Aps deficiency in B cells results in augmented depletion of IgE+ blasts by B cell receptor crosslinking (anti-CD79b), suggesting SH2B2/APS promotes survival of GC B cells and IgE+ plasma cells downstream of BCR signaling. Genetic knockout mice (Aps−/−), in vivo immunization, flow cytometry for GC B cell frequencies/apoptosis, in vitro B cell culture system with BCR crosslinking Scientific reports Medium 39090233
2025 SH2B2 is downregulated in MPTP-induced mouse PD model and MPP+-treated SH-SY5Y cells; overexpression of SH2B2 reversed MPP+-induced cell viability reduction and apoptosis in SH-SY5Y cells, upregulated tyrosine hydroxylase (TH) expression, downregulated IBA1 levels (neuroinflammation marker), and improved motor function in MPTP mice, indicating a neuroprotective role for SH2B2 in dopaminergic neurons. In vivo MPTP mouse model with lentiviral SH2B2 overexpression; in vitro MPP+-treated SH-SY5Y cells with OE-SH2B2; behavioral tests, CCK-8 viability assay, flow cytometry (apoptosis), Western blot, IHC Neuroscience Medium 41482210

Source papers

Stage 0 corpus · 23 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2021 Insulin signaling in health and disease. The Journal of clinical investigation 334 33393497
2011 The adaptor Lnk (SH2B3): an emerging regulator in vascular cells and a link between immune and inflammatory signaling. Biochemical pharmacology 113 21723852
2013 The insulin receptor: both a prototypical and atypical receptor tyrosine kinase. Cold Spring Harbor perspectives in biology 112 23457259
2014 SH2B1 regulation of energy balance, body weight, and glucose metabolism. World journal of diabetes 76 25126397
2021 Epigenetic age prediction in semen - marker selection and model development. Aging 41 34375949
2007 Identification of SH2B2beta as an inhibitor for SH2B1- and SH2B2alpha-promoted Janus kinase-2 activation and insulin signaling. Endocrinology 36 17204555
2017 Inflammation-Related Gene Polymorphisms Associated With Primary Immune Thrombocytopenia. Frontiers in immunology 33 28702029
2009 Nucleocytoplasmic shuttling of the adapter protein SH2B1beta (SH2-Bbeta) is required for nerve growth factor (NGF)-dependent neurite outgrowth and enhancement of expression of a subset of NGF-responsive genes. Molecular endocrinology (Baltimore, Md.) 27 19372237
2011 The adaptor protein SH2B3 (Lnk) negatively regulates neurite outgrowth of PC12 cells and cortical neurons. PloS one 25 22028877
2013 Hepatic SH2B1 and SH2B2 regulate liver lipid metabolism and VLDL secretion in mice. PloS one 24 24358267
2012 Preeclampsia: a bioinformatics approach through protein-protein interaction networks analysis. BMC systems biology 22 22873350
2021 Hypertension in African Populations: Review and Computational Insights. Genes 17 33917487
2017 Single nucleotide polymorphism discovery in bovine liver using RNA-seq technology. PloS one 8 28234981
2013 Effect of genetic variations within the SH2B2 gene on the growth of Chinese cattle. Gene 8 23860327
2021 Bioinformatics screening of ETV4 transcription factor oncogenes and identifying small-molecular anticancer drugs. Chemical biology & drug design 5 34757684
2025 Effects of dietary oregano essential oil supplementation on carcass traits, muscle fiber structure, oxidative stability, meat quality, and regulatory mechanisms in Holstein steers. Journal of the science of food and agriculture 4 39821900
2025 Multi-omics integration to identify immune-associated biomarkers and potential therapeutics in periodontitis. Frontiers in medicine 1 41140666
2025 Investigations on the effects of SH2B2 on Parkinson's disease based on its in vivo and in vitro neurotoxic model. Neuroscience 1 41482210
2024 Control of germinal center B cell survival and IgE production by an adaptor molecule containing PH and SH2 domains, Aps/Sh2b2. Scientific reports 1 39090233
2008 [Sh2b3/Lnk family adaptor proteins in the regulation of lymphohematopoiesis]. Nihon Rinsho Men'eki Gakkai kaishi = Japanese journal of clinical immunology 1 19122374
1998 The genomic and sequence analysis of rat histone H2B genes. DNA sequence : the journal of DNA sequencing and mapping 1 10524764
2025 Expression analysis of the adaptor proteins Sh2b family during zebrafish embryonic development. Gene expression patterns : GEP 0 40915553
2025 Causal Associations Between Smoking, Brain Structural Alterations and Psychiatric Disorders: Evidence From a Mediation Analysis. Addiction biology 0 41289983

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