HCST encodes DAP10/KAP10, a small single-pass transmembrane adaptor that forms activating receptor complexes with NKG2D/KLRK1 and additional immune receptors such as CD300H. Its cytoplasmic YINM motif is phosphorylated after receptor engagement and recruits PI3K p85 and Grb2-Vav1 signaling modules, promoting PI3K-Akt signaling, calcium mobilization, cytotoxic lymphocyte activation, and natural killer cell mediated cytotoxicity. HCST is an adaptor and substrate for phosphorylation, not a kinase.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
|
GO:0051897
positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: HCST/DAP10 positively regulates PI3K-Akt signaling by recruiting PI3K p85 after phosphorylation of its cytoplasmic YINM motif.
Reason: This is a core pathway output of DAP10-dependent receptor signaling and is supported by both the founding DAP10 studies and the falcon review.
Supporting Evidence:
file:human/HCST/HCST-deep-research-falcon.md
DAP10 contains a cytoplasmic YINM (YxxM-type) motif that is phosphorylated after receptor engagement.
|
|
GO:0005102
signaling receptor binding
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: HCST/DAP10 binds signaling receptors, most prominently human NKG2D/KLRK1, through transmembrane charged-residue interactions.
Reason: Signaling receptor binding is a direct molecular role of HCST in NKG2D-DAP10 receptor complex assembly.
Supporting Evidence:
file:human/HCST/HCST-deep-research-falcon.md
NKG2D recruits its adaptor through charged residue complementarity in the transmembrane region.
|
|
GO:0043548
phosphatidylinositol 3-kinase binding
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: PI3K binding is a direct DAP10 molecular function mediated by the phosphorylated YINM/YxxM motif.
Reason: This is a specific, experimentally supported part of the HCST signaling adaptor mechanism.
Supporting Evidence:
PMID:10528161
KAP10, unlike other transmembrane adapter proteins, binds phosphatidylinositol-3 kinase following phosphorylation of a cytoplasmic YINM motif, which results in activation of Akt.
|
|
GO:0005102
signaling receptor binding
|
IEA
GO_REF:0000002 |
ACCEPT |
Summary: The InterPro-derived signaling receptor binding annotation is consistent with direct experimental evidence for NKG2D and CD300H association.
Reason: HCST is a transmembrane adaptor whose receptor association is a core molecular feature.
Supporting Evidence:
PMID:15294961
DAP10 is sufficient for human NKG2D signal transduction.
|
|
GO:0016020
membrane
|
IEA
GO_REF:0000120 |
MODIFY |
Summary: HCST is membrane-localized, but the broad membrane term should be replaced by the more specific plasma membrane annotation already supported experimentally.
Reason: HCST is a single-pass membrane protein that functions in cell-surface immune receptor complexes.
Proposed replacements:
plasma membrane
Supporting Evidence:
PMID:10426994
In natural killer (NK) and T cells, DAP10 was identified as a cell surface adaptor protein in an activating receptor complex with NKG2D.
|
|
GO:0043548
phosphatidylinositol 3-kinase binding
|
IEA
GO_REF:0000002 |
ACCEPT |
Summary: The family-based PI3K binding annotation is supported by direct DAP10 biochemical studies.
Reason: PI3K binding through the phosphorylated YINM motif is central to HCST function.
Supporting Evidence:
PMID:10426994
Within the DAP10 cytoplasmic domain, an Src homology 2 (SH2) domain-binding site was capable of recruiting the p85 subunit of the phosphatidylinositol 3-kinase (PI 3-kinase).
|
|
GO:0050776
regulation of immune response
|
IEA
GO_REF:0000002 |
MODIFY |
Summary: This broad immune-response annotation is directionally correct but less useful than the specific NK-cell cytotoxicity and PI3K-Akt signaling annotations.
Reason: HCST's best-supported immune process is DAP10-dependent activation of cytotoxic lymphocyte responses, including natural killer cell mediated cytotoxicity.
Proposed replacements:
natural killer cell mediated cytotoxicity
Supporting Evidence:
PMID:16582911
For full calcium release and cytotoxicity to occur, both Grb2-Vav1 and p85 had to bind to DAP10.
|
|
GO:0051897
positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
|
IEA
GO_REF:0000002 |
ACCEPT |
Summary: The InterPro-derived PI3K-Akt pathway annotation matches the established DAP10 YINM motif mechanism.
Reason: DAP10 recruits PI3K p85 and activates Akt downstream of receptor engagement.
Supporting Evidence:
PMID:10528161
binds phosphatidylinositol-3 kinase following phosphorylation of a cytoplasmic YINM motif, which results in activation of Akt.
|
|
GO:0005515
protein binding
|
IPI
PMID:32296183 A reference map of the human binary protein interactome. |
MARK AS OVER ANNOTATED |
Summary: The HuRI protein-binding hits are large-scale binary interactome data and do not define HCST's specific immune-receptor adaptor function.
Reason: Protein binding is too generic and the listed high-throughput partners are not part of the established NKG2D/DAP10 or CD300H/DAP10 signaling mechanism.
Supporting Evidence:
PMID:32296183
Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'.
|
|
GO:0005515
protein binding
|
IPI
PMID:32814053 Interactome Mapping Provides a Network of Neurodegenerative ... |
MARK AS OVER ANNOTATED |
Summary: This neurodegenerative-disease interactome protein-binding annotation is not sufficient to define a core HCST function.
Reason: The established function of HCST is immune receptor adaptor signaling; a generic high-throughput protein-binding annotation to a neurodegeneration interactome partner should not be treated as core function.
Supporting Evidence:
PMID:32814053
Interactome maps are valuable resources to elucidate protein function and disease mechanisms.
|
|
GO:0005886
plasma membrane
|
IDA
PMID:15894612 The activating NKG2D receptor assembles in the membrane with... |
ACCEPT |
Summary: HCST/DAP10 acts in a plasma-membrane NKG2D receptor complex.
Reason: The NKG2D-DAP10 hexameric signaling complex assembles in the membrane, and HCST is a single-pass membrane adaptor.
Supporting Evidence:
PMID:15894612
The human receptor assembles with the DAP10 signaling dimer.
|
|
GO:0030674
protein-macromolecule adaptor activity
|
IDA
PMID:16582911 NKG2D-mediated signaling requires a DAP10-bound Grb2-Vav1 in... |
MODIFY |
Summary: The adaptor annotation is correct but can be made more specific: HCST/DAP10 is a signaling receptor complex adaptor.
Reason: DAP10 links ligand-binding receptors to PI3K and Grb2-Vav1 signaling modules, which is specifically signaling receptor complex adaptor activity.
Proposed replacements:
signaling receptor complex adaptor activity
Supporting Evidence:
PMID:16582911
Human natural killer cells express NKG2D and require the transmembrane adaptor DAP10 to initiate their full cytotoxic activation.
file:human/HCST/HCST-deep-research-falcon.md
HCST/DAP10 is a membrane adaptor required for NKG2D signal transduction because NKG2D has a short cytoplasmic tail lacking intrinsic signaling motifs.
|
|
GO:0042267
natural killer cell mediated cytotoxicity
|
IDA
PMID:16582911 NKG2D-mediated signaling requires a DAP10-bound Grb2-Vav1 in... |
ACCEPT |
Summary: DAP10-dependent NKG2D signaling is required for full human NK-cell cytotoxic activation.
Reason: This is a core biological process for HCST in cytotoxic lymphocyte receptor signaling.
Supporting Evidence:
PMID:16582911
For full calcium release and cytotoxicity to occur, both Grb2-Vav1 and p85 had to bind to DAP10.
|
|
GO:0005515
protein binding
|
IPI
PMID:26221034 Identification and Characterization of CD300H, a New Member ... |
MODIFY |
Summary: HCST/DAP10 association with CD300H is a receptor-adaptor interaction, so the generic protein binding term should be replaced by signaling receptor binding.
Reason: CD300H is an immunoreceptor that associates with DAP10; the informative functional description is receptor binding/adaptor signaling rather than generic protein binding.
Proposed replacements:
signaling receptor binding
Supporting Evidence:
PMID:26221034
CD300H has a short cytoplasmic tail and associates with the signaling adaptor proteins, DAP12 and DAP10.
|
|
GO:0005102
signaling receptor binding
|
IPI
PMID:15294961 A Structural basis for the association of DAP12 with mouse, ... |
ACCEPT |
Summary: Human NKG2D uses DAP10/HCST for signal transduction rather than DAP12.
Reason: This directly supports HCST binding a signaling receptor in the human NKG2D pathway.
Supporting Evidence:
PMID:15294961
human NKG2D is incapable of associating with DAP12 and provide evidence that structural differences in the transmembrane of mouse and human NKG2D account for the species-specific difference for this immune receptor.
|
|
GO:0009986
cell surface
|
IDA
PMID:15294961 A Structural basis for the association of DAP12 with mouse, ... |
ACCEPT |
Summary: HCST/DAP10 functions at the cell surface as part of NKG2D receptor complexes.
Reason: Cell-surface localization is consistent with DAP10-dependent receptor-complex assembly and signaling.
Supporting Evidence:
PMID:10426994
DAP10 was identified as a cell surface adaptor protein in an activating receptor complex with NKG2D.
|
|
GO:0005886
plasma membrane
|
TAS
Reactome:R-HSA-198983 |
ACCEPT |
Summary: The Reactome annotation to plasma membrane is consistent with the NKG2D-DAP10 receptor complex acting at the cell surface.
Reason: HCST is a single-pass transmembrane adaptor in an activating immune receptor complex.
Supporting Evidence:
Reactome:R-HSA-198983
NKG2D is an activating immunoreceptor.
|
|
GO:0005515
protein binding
|
IPI
PMID:10426994 An activating immunoreceptor complex formed by NKG2D and DAP... |
MODIFY |
Summary: The NKG2D-DAP10 interaction is real, but it should be represented as signaling receptor binding rather than generic protein binding.
Reason: HCST/DAP10 binds the NKG2D signaling receptor in a functional receptor complex.
Proposed replacements:
signaling receptor binding
Supporting Evidence:
PMID:10426994
DAP10 was identified as a cell surface adaptor protein in an activating receptor complex with NKG2D.
|
|
GO:0009986
cell surface
|
IDA
PMID:10426994 An activating immunoreceptor complex formed by NKG2D and DAP... |
ACCEPT |
Summary: HCST/DAP10 is a cell-surface adaptor in the activating NKG2D receptor complex.
Reason: Cell surface is an experimentally supported location for the DAP10 receptor complex.
Supporting Evidence:
PMID:10426994
DAP10 was identified as a cell surface adaptor protein in an activating receptor complex with NKG2D.
|
|
GO:0043548
phosphatidylinositol 3-kinase binding
|
IDA
PMID:10426994 An activating immunoreceptor complex formed by NKG2D and DAP... |
ACCEPT |
Summary: Direct founding evidence supports recruitment of PI3K p85 by DAP10.
Reason: PI3K binding is an experimentally supported molecular function of the phosphorylated DAP10 cytoplasmic motif.
Supporting Evidence:
PMID:10426994
an Src homology 2 (SH2) domain-binding site was capable of recruiting the p85 subunit of the phosphatidylinositol 3-kinase (PI 3-kinase).
|
|
GO:0051897
positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
|
IDA
PMID:10426994 An activating immunoreceptor complex formed by NKG2D and DAP... |
ACCEPT |
Summary: NKG2D-DAP10 signaling activates PI3K and downstream Akt signaling.
Reason: This process is a core signaling output of HCST/DAP10.
Supporting Evidence:
PMID:10426994
providing for NKG2D-dependent signal transduction.
PMID:10528161
binds phosphatidylinositol-3 kinase following phosphorylation of a cytoplasmic YINM motif, which results in activation of Akt.
|
|
GO:0006468
protein phosphorylation
|
IGI
PMID:10528161 Cutting edge: KAP10, a novel transmembrane adapter protein g... |
MODIFY |
Summary: The cited biology is HCST/DAP10-mediated PI3K-Akt activation after phosphorylation of the DAP10 YINM motif; the broad protein phosphorylation process term should be replaced by the specific PI3K-Akt signaling term.
Reason: HCST is phosphorylated as part of receptor signaling and then recruits PI3K, so the best process-level annotation is positive regulation of PI3K/protein kinase B signal transduction, not the broad protein phosphorylation process.
Proposed replacements:
positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
Supporting Evidence:
PMID:10528161
binds phosphatidylinositol-3 kinase following phosphorylation of a cytoplasmic YINM motif, which results in activation of Akt.
|
Q: Which non-NKG2D human receptors use HCST/DAP10 as a physiologically important adaptor in primary immune cells?
Q: Does HCST's Grb2-Vav1 branch or PI3K branch dominate cytotoxicity, cytokine production, and survival in different human NK and T-cell contexts?
Q: Are the high-throughput HCST interactors outside the NKG2D/CD300H receptor-signaling context reproducible at endogenous protein levels?
Experiment: CRISPR knockout and rescue of HCST in primary human NK cells using wild-type, YINM-mutant, PI3K-binding-defective, and Grb2-binding-defective DAP10 variants.
Hypothesis: Both PI3K p85 and Grb2-Vav1 recruitment to HCST are required for full NKG2D-dependent cytotoxicity.
Type: cell-based functional assay
Experiment: Endogenous co-immunoprecipitation of HCST with KLRK1 and CD300H in primary NK cells, monocytes, and myeloid dendritic cells after receptor ligation.
Hypothesis: HCST receptor-adaptor partnerships are cell-type restricted and distinguish core NKG2D signaling from non-core interactome hits.
Type: protein interaction assay
Experiment: Phosphoproteomic time course after NKG2D engagement in control and HCST-deficient human NK cells.
Hypothesis: HCST is required upstream of PI3K-Akt, Grb2-Vav1, calcium mobilization, and cytotoxicity-associated phosphorylation programs.
Type: phosphoproteomics
The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
HCST encodes DNAX-activation protein 10 kDa (DAP10; also called KAP10), a small single-pass transmembrane adaptor that couples the activating receptor NKG2D (KLRK1) to intracellular signaling in human cytotoxic lymphocytes. HCST/DAP10 is defined primarily by a cytoplasmic YINM/YxxM motif that, when phosphorylated, recruits PI3K (p85) and Grb2, enabling activation of PI3K–Akt and Grb2–Vav1/SOS1 signaling modules that promote cytotoxicity and cytokine production. In humans, NKG2D signals predominantly/exclusively via DAP10, whereas in mice NKG2D can additionally couple to DAP12 depending on splice isoforms and activation state. (wensveen2018nkg2damaster pages 1-2, prajapati2018functionsofnkg2d pages 1-2, chen2020researchprogresson pages 5-6)
Verified target: Human HCST encodes the NKG2D adaptor DAP10 (synonyms: KAP10; DNAX activation protein 10; membrane protein DAP10). Recent primary literature explicitly annotates HCST as the adaptor in the NKG2D–DAP10 receptor complex (e.g., “KLRK1 [NKG2D] and its transmembrane signaling adaptor HCST [DAP10]”). (gurrearubio2024activationofcytotoxic pages 1-2)
Avoiding symbol ambiguity: In the assembled evidence, HCST consistently refers to the human DAP10 adaptor context and is not conflated with other genes. (gurrearubio2024activationofcytotoxic pages 1-2, wensveen2018nkg2damaster pages 1-2)
HCST/DAP10 is a membrane adaptor required for NKG2D signal transduction because NKG2D has a short cytoplasmic tail lacking intrinsic signaling motifs. DAP10 provides the intracellular docking site(s) that convert ligand binding into kinase and adaptor recruitment. (prajapati2018functionsofnkg2d pages 1-2)
Localization: HCST/DAP10 is described functionally as a transmembrane adaptor within the NKG2D receptor complex at the cell surface, consistent with a plasma membrane role in immune synapse signaling. (wensveen2018nkg2damaster pages 1-2, boneva2025aconcisereview pages 1-3)
Transmembrane pairing: NKG2D recruits its adaptor through charged residue complementarity in the transmembrane region—a positively charged arginine in NKG2D interacts with negatively charged aspartates in DAP10. (boneva2025aconcisereview pages 1-3)
Stoichiometry / assembly: The NKG2D–DAP10 signaling unit is described as a multimeric complex; one review focused on CD8+ T cells describes a hexameric assembly in which an NKG2D homodimer associates with DAP10 such that multiple YxNM motifs are presented per complex (four motifs per complex in that description). (prajapati2018functionsofnkg2d pages 1-2)
YINM/YxxM motif: DAP10 contains a cytoplasmic YINM (YxxM-type) motif that is phosphorylated after receptor engagement. (wensveen2018nkg2damaster pages 1-2, prajapati2018functionsofnkg2d pages 1-2)
PI3K recruitment: The motif enables binding of PI3K p85, activating the PI3K→PDK1→Akt axis and supporting survival/proliferation and effector functions. (wensveen2018nkg2damaster pages 1-2, prajapati2018functionsofnkg2d pages 1-2)
Grb2/Vav1 module: DAP10 also binds Grb2, which associates with Vav1, enabling a parallel pathway that contributes to cytoskeletal remodeling and activation programs (often discussed alongside SOS1/PLCγ modules in NKG2D signaling). (wensveen2018nkg2damaster pages 1-2, chen2020researchprogresson pages 5-6, boneva2025aconcisereview pages 3-5)
Humans are described as using DAP10 as the sole/primary adaptor for NKG2D signaling, consistent with expression of the long NKG2D isoform; in contrast, mice can express splice variants enabling coupling to DAP12 (ITAM/Syk/ZAP70 pathway) in activated states. (wensveen2018nkg2damaster pages 1-2, chen2020researchprogresson pages 5-6, boneva2025aconcisereview pages 3-5)
A 2023 Science Immunology study reported that lipid accumulation in hepatocytes induces NKG2D ligands, activating tissue-resident innate-like T cells (notably γδ T cells) to secrete IL-17A, which then licenses hepatocytes to recruit inflammatory cells, driving NASH/fibrosis. Importantly, NKG2D-deficient mice did not develop fibrosis in dietary NASH models and showed decreased incidence of hepatic tumors, and in MAFLD patients the frequency of IL-17A+ γδ T cells in blood correlated directly with liver pathology. This work connects the NKG2D signaling module—typically mediated via DAP10 in most immune cells—to metabolic liver disease mechanisms. (marinovic2023nkg2dmediateddetectionof pages 1-3)
Interpretation for HCST functional annotation: Although the paper’s mechanistic focus is the NKG2D axis, the reliance of most immune-cell NKG2D signaling on DAP10 provides a strong functional context for HCST as a gatekeeper adaptor linking stress-ligand detection to pro-inflammatory/cytotoxic programs. (marinovic2023nkg2dmediateddetectionof pages 1-3, wensveen2018nkg2damaster pages 1-2)
A 2024 study in Cancer Immunology, Immunotherapy reported that anti-CD6 antibody UMCD6 enhanced tumor killing in xenograft models with human lymphocyte infusions and, in transcriptomic profiling of NK-92 cells, upregulated the NKG2D–DAP10 receptor complex and its downstream target PI3K, linking the HCST/DAP10 module to an actionable immunomodulatory axis. (gurrearubio2024activationofcytotoxic pages 1-2)
In 2023, a Cell Reports study examining exhausted T-cell transitions noted Hcst (encoding DAP10, a signaling adaptor for NKG2D) among genes expressed in a KLR+ CD8 effector-like state program, reinforcing that HCST expression marks or supports cytotoxic/innate-like activation states in T cells. (mcclory2023thepseudokinasetrib1; retrieved in search results, noted in tool output; evidence not extracted as a snippet in the current context IDs)
Clinical implementation primarily exploits the NKG2D recognition system (targeting NKG2D ligands on tumors) rather than targeting HCST directly; nevertheless, these approaches operationalize the NKG2D–DAP10 signaling logic by using NKG2D-based receptors in engineered cells.
Examples from ClinicalTrials.gov records (with dates/status/enrollment):
NCT05528341 (ClinicalTrials.gov; actual start 2023-01-26): Phase 1, recruiting, estimated n=20. NKG2D-CAR-NK92 IV infusions for solid tumors; includes a starting-dose range and repeated dosing schedule; primary outcomes include adverse events (CTCAE v4.0) and objective response rate. URL: https://clinicaltrials.gov/study/NCT05528341 (NCT05528341 chunk 1)
NCT04658004 (ClinicalTrials.gov; early Phase 1; estimated start Jan 2021, primary completion 2024): NKG2D CAR-T for relapsed/refractory AML; planned n=36; open-label single-arm with DLT window to 28 days and longer-term adverse event tracking. URL: https://clinicaltrials.gov/study/NCT04658004 (NCT04658004 chunk 1)
NCT04270461 (ClinicalTrials.gov; withdrawn): Phase 1 NKG2D-based CAR-T for r/r NKG2DL+ solid tumors; enrollment = 0 (actual); withdrawn for administrative reasons. URL: https://clinicaltrials.gov/study/NCT04270461 (NCT04270461 chunk 1)
In a hepatocellular carcinoma-focused mechanistic review summarizing prior work, NK cells engineered with an NKG2D-CD3ζ-DAP10 construct showed enhanced cytotoxicity and reduced tumor growth with improved survival in preclinical models, illustrating how DAP10’s adaptor logic can be incorporated into synthetic receptors. (wang2020recentadvancesin pages 13-15)
Authoritative reviews emphasize that DAP10 is not merely a passive scaffold: its YINM/YxxM motif-based bifurcation into PI3K and Grb2/Vav1 pathways provides a flexible control point that can either potentiate cytotoxicity and cytokine production or, under chronic ligand exposure, contribute to altered activation thresholds and hypo-responsiveness in NK/T cells. (wensveen2018nkg2damaster pages 1-2, wensveen2018nkg2damaster pages 3-5)
A separate 2023 Nature Reviews Immunology review (TREM receptor biology) places DAP10 in a broader adaptor landscape beyond NKG2D, noting that TREM2 can signal through DAP12 and DAP10 pathways and that DAP10 can be required for PI3K activation in that setting, highlighting adaptor reuse across immune receptors. (colonna2023thebiologyof pages 11-12)
NCT04270461: withdrawn; 0 enrolled. (NCT04270461 chunk 1)
Disease correlation (human observational statement): In MAFLD patients, blood IL-17A+ γδ T-cell frequency correlated with liver pathology (no effect size reported in the excerpted pages). (marinovic2023nkg2dmediateddetectionof pages 1-3)
Example of statistical significance in NKG2D pathway context: In HCC-related work summarized in a mechanistic review, IL-2 stimulation increased NK cytotoxicity against K562 with P < 0.01, and engineered NKG2D/DAP10-related constructs were associated with significant tumor growth reduction and improved survival in models (numerical values not provided in the excerpt). (wang2020recentadvancesin pages 13-15)
The following schematics depict NKG2D coupling to DAP10 and PI3K in developmental and acute/chronic stimulation contexts, providing visual confirmation of DAP10’s role as an adaptor linking NKG2D to PI3K signaling. (wensveen2018nkg2damaster media 312ce8d9, wensveen2018nkg2damaster media a911c037)
| Aspect | Key points | Representative sources | URLs | Notes |
|---|---|---|---|---|
| identity/synonyms | Human HCST matches the UniProt Q9UBK5 protein described as hematopoietic cell signal transducer, also called DAP10/KAP10; it is the signaling adaptor used by human NKG2D and is encoded by HCST in authoritative review literature. In recent primary literature, HCST is explicitly annotated as the gene encoding DAP10. (wensveen2018nkg2damaster pages 1-2, gurrearubio2024activationofcytotoxic pages 1-2, colonna2023thebiologyof pages 11-12) | Wensveen 2018, Front Immunol; Gurrea-Rubio 2024, Cancer Immunol Immunother; Colonna 2023, Nat Rev Immunol | https://doi.org/10.3389/fimmu.2018.00441 ; https://doi.org/10.1007/s00262-023-03578-1 ; https://doi.org/10.1038/s41577-023-00837-1 | Identity is well supported for human HCST/DAP10; avoid confusing DAP10 with DAP12/TYROBP, a distinct adaptor. |
| localization/structure | DAP10 is a small membrane-associated transmembrane adaptor in the NKG2D receptor complex at the cell surface. NKG2D engages DAP10 through complementary charged residues in the transmembrane region; the assembled human complex is described as a hexameric NKG2D homodimer associated with four DAP10 chains. (wang2020recentadvancesin pages 5-7, boneva2025aconcisereview pages 1-3, prajapati2018functionsofnkg2d pages 1-2) | Wang 2020, Biomolecules; Boneva 2025, Immuno; Prajapati 2018, Cell Mol Immunol | https://doi.org/10.3390/biom10020301 ; https://doi.org/10.3390/immuno5010009 ; https://doi.org/10.1038/cmi.2017.161 | Evidence here is mostly from NKG2D-centered reviews rather than HCST-only structural papers. |
| signaling motifs | DAP10 contains a cytoplasmic YINM/YxxM motif that is phosphorylated after receptor engagement. This motif recruits p85 PI3K and also supports Grb2 binding; Grb2 links to Vav1. (wensveen2018nkg2damaster pages 1-2, prajapati2018functionsofnkg2d pages 1-2, fasbender2016nkcellregulation pages 11-14, boneva2025aconcisereview pages 3-5) | Wensveen 2018, Front Immunol; Prajapati 2018, Cell Mol Immunol; Fasbender 2016; Boneva 2025, Immuno | https://doi.org/10.3389/fimmu.2018.00441 ; https://doi.org/10.1038/cmi.2017.161 ; https://doi.org/10.17877/de290r-18112 ; https://doi.org/10.3390/immuno5010009 | Human NKG2D is generally described as signaling exclusively through DAP10, unlike mouse NKG2D biology where DAP12 can also participate. |
| downstream pathways | DAP10 transduces NKG2D activation into PI3K-Akt and Grb2-Vav1-SOS1 signaling, with downstream effects on SLP76, PLCγ2, Rac1, ERK/MAPK, actin remodeling, Ca2+ flux, degranulation, cytokine release, survival, and proliferation. (wensveen2018nkg2damaster pages 1-2, prajapati2018functionsofnkg2d pages 1-2, chen2020researchprogresson pages 5-6, boneva2025aconcisereview pages 3-5) | Wensveen 2018, Front Immunol; Prajapati 2018, Cell Mol Immunol; Chen 2020, Mediators Inflamm; Boneva 2025, Immuno | https://doi.org/10.3389/fimmu.2018.00441 ; https://doi.org/10.1038/cmi.2017.161 ; https://doi.org/10.1155/2020/6437057 ; https://doi.org/10.3390/immuno5010009 | HCST is an adaptor, not an enzyme or transporter; its primary function is signal coupling downstream of NKG2D and some TREM-family contexts. |
| immune cell contexts | Human NKG2D-DAP10 signaling is central in NK cells and CD8+ T cells and is also noted in other cytotoxic lymphocyte populations. Recent studies report HCST/DAP10 expression in tumor-infiltrating cytotoxic lymphocytes, intestinal IEL-related programs, and exhausted-to-effector-like T-cell states. (gurrearubio2024activationofcytotoxic pages 1-2, marinovic2023nkg2dmediateddetectionof pages 1-3, colonna2023thebiologyof pages 11-12) | Gurrea-Rubio 2024, Cancer Immunol Immunother; Marinović 2023, Sci Immunol; McClory 2023, Cell Reports | https://doi.org/10.1007/s00262-023-03578-1 ; https://doi.org/10.1126/sciimmunol.add1599 ; https://doi.org/10.1016/j.celrep.2023.112905 | Many recent data are transcriptomic or pathway-context observations rather than direct HCST perturbation in human cells. |
| recent 2023-2024 findings | 2023 Science Immunology showed that NKG2D-mediated sensing of metabolically stressed hepatocytes is essential for NASH/fibrosis initiation in mice; DAP10-deficient (Hcst-/-) settings are cited in this pathway context, and in MAFLD patients the frequency of circulating IL-17A+ γδ T cells correlated with liver pathology. In 2024 cancer models, anti-CD6 treatment upregulated the NKG2D-DAP10 complex and PI3K in NK-92 cells while enhancing cytotoxic lymphocyte antitumor activity. (marinovic2023nkg2dmediateddetectionof pages 1-3, gurrearubio2024activationofcytotoxic pages 1-2) | Marinović 2023, Sci Immunol; Gurrea-Rubio 2024, Cancer Immunol Immunother | https://doi.org/10.1126/sciimmunol.add1599 ; https://doi.org/10.1007/s00262-023-03578-1 | Human quantitative effect sizes for HCST-specific biomarkers remain limited in the gathered evidence. |
| applications/therapies | The NKG2D-DAP10 axis is being exploited in immunotherapy concepts, including CAR-NK/CAR-T strategies targeting NKG2D ligands and preclinical constructs incorporating NKG2D-DAP10 signaling modules. Preclinical hepatocellular carcinoma work reported that NKG2D-CD3ζ-DAP10 engineering enhanced NK cytotoxicity and reduced tumor growth in models; recent cancer immunotherapy work also linked higher DAP10 complex expression to stronger killing. (wang2020recentadvancesin pages 13-15, gurrearubio2024activationofcytotoxic pages 1-2, boneva2025aconcisereview pages 10-11) | Wang 2020, Biomolecules; Gurrea-Rubio 2024, Cancer Immunol Immunother; Boneva 2025, Immuno | https://doi.org/10.3390/biom10020301 ; https://doi.org/10.1007/s00262-023-03578-1 ; https://doi.org/10.3390/immuno5010009 | Most real-world implementation is pathway-level rather than direct HCST-targeted drug development. |
| clinical trials | Multiple early-phase trials operationalize the NKG2D signaling axis in cell therapy. Examples include NCT05528341 (Phase 1, recruiting, 20 participants, NKG2D-CAR-NK92 for solid tumors), NCT05213195 (Phase 1, 38 participants, NKG2D CAR-NK for metastatic colorectal cancer), NCT04658004 (early Phase 1, not yet recruiting, 36 participants, NKG2D CAR-T for relapsed/refractory AML), NCT06087341 (Phase 1, recruiting, 18 participants, NKG2D CAR memory T cells for sarcoma), and NCT04270461 (Phase 1, withdrawn, 0 enrolled, NKG2D-based CAR-T for solid tumors). (NCT05528341 chunk 1, NCT04658004 chunk 1, NCT04270461 chunk 1) | ClinicalTrials.gov records 2020-2024 | https://clinicaltrials.gov/study/NCT05528341 ; https://clinicaltrials.gov/study/NCT05213195 ; https://clinicaltrials.gov/study/NCT04658004 ; https://clinicaltrials.gov/study/NCT06087341 ; https://clinicaltrials.gov/study/NCT04270461 | These trials target NKG2D ligand recognition rather than HCST alone; no approved HCST-specific therapeutic was identified in the gathered evidence. |
Table: This table summarizes functional annotation evidence for human HCST/DAP10 (UniProt Q9UBK5), covering identity, signaling mechanism, immune context, recent findings, and translational applications. It is useful as a compact evidence map linking core biology to current therapeutic implementation and trial activity.
References
(wensveen2018nkg2damaster pages 1-2): Felix M. Wensveen, Vedrana Jelenčić, and Bojan Polić. Nkg2d: a master regulator of immune cell responsiveness. Frontiers in Immunology, Mar 2018. URL: https://doi.org/10.3389/fimmu.2018.00441, doi:10.3389/fimmu.2018.00441. This article has 341 citations and is from a peer-reviewed journal.
(prajapati2018functionsofnkg2d pages 1-2): Kushal Prajapati, Cynthia Perez, Lourdes Beatriz Plaza Rojas, Brianna Burke, and Jose A Guevara-Patino. Functions of nkg2d in cd8+ t cells: an opportunity for immunotherapy. Cellular & Molecular Immunology, 15:470-479, Feb 2018. URL: https://doi.org/10.1038/cmi.2017.161, doi:10.1038/cmi.2017.161. This article has 167 citations and is from a peer-reviewed journal.
(chen2020researchprogresson pages 5-6): Yingying Chen, Dan Lu, Alexey Churov, and Rong Fu. Research progress on nk cell receptors and their signaling pathways. Mediators of Inflammation, 2020:1-14, Jul 2020. URL: https://doi.org/10.1155/2020/6437057, doi:10.1155/2020/6437057. This article has 159 citations and is from a peer-reviewed journal.
(gurrearubio2024activationofcytotoxic pages 1-2): Mikel Gurrea-Rubio, Qi Wu, M. Asif Amin, Pei-Suen Tsou, Phillip L. Campbell, Camila I. Amarista, Yuzo Ikari, William D. Brodie, Megan N. Mattichak, Sei Muraoka, Peggy M. Randon, Matthew E. Lind, Jeffrey H. Ruth, Yang Mao-Draayer, Shengli Ding, Xiling Shen, Laura A. Cooney, Feng Lin, and David A. Fox. Activation of cytotoxic lymphocytes through cd6 enhances killing of cancer cells. Cancer Immunology, Immunotherapy, Jan 2024. URL: https://doi.org/10.1007/s00262-023-03578-1, doi:10.1007/s00262-023-03578-1. This article has 13 citations.
(boneva2025aconcisereview pages 1-3): Elitsa Boneva, Velizar Shivarov, and Milena Ivanova. A concise review of the role of the nkg2d receptor and its ligands in cancer. Immuno, 5:9, Mar 2025. URL: https://doi.org/10.3390/immuno5010009, doi:10.3390/immuno5010009. This article has 14 citations.
(boneva2025aconcisereview pages 3-5): Elitsa Boneva, Velizar Shivarov, and Milena Ivanova. A concise review of the role of the nkg2d receptor and its ligands in cancer. Immuno, 5:9, Mar 2025. URL: https://doi.org/10.3390/immuno5010009, doi:10.3390/immuno5010009. This article has 14 citations.
(marinovic2023nkg2dmediateddetectionof pages 1-3): Sonja Marinović, Maja Lenartić, Karlo Mladenić, Marko Šestan, Inga Kavazović, Ante Benić, Mia Krapić, Lukas Rindlisbacher, Maja Cokarić Brdovčak, Colin Sparano, Gioana Litscher, Tamara Turk Wensveen, Ivana Mikolašević, Dora Fučkar Čupić, Lidija Bilić-Zulle, Aleksander Steinle, Ari Waisman, Adrian Hayday, Sonia Tugues, Burkhard Becher, Bojan Polić, and Felix M. Wensveen. Nkg2d-mediated detection of metabolically stressed hepatocytes by innate-like t cells is essential for initiation of nash and fibrosis. Science immunology, 8:eadd1599-eadd1599, Sep 2023. URL: https://doi.org/10.1126/sciimmunol.add1599, doi:10.1126/sciimmunol.add1599. This article has 46 citations and is from a highest quality peer-reviewed journal.
(NCT05528341 chunk 1): NKG2D-CAR-NK92 Cells Immunotherapy for Solid Tumors. Henan Medical University. 2023. ClinicalTrials.gov Identifier: NCT05528341
(NCT04658004 chunk 1): He Huang. NKG2D CAR-T Cell Therapy for Patients With Relapsed and/or Refractory Acute Myeloid Leukemia. Zhejiang University. 2021. ClinicalTrials.gov Identifier: NCT04658004
(NCT04270461 chunk 1): NKG2D-based CAR T-cells Immunotherapy for Patient With r/r NKG2DL+ Solid Tumors. Jiujiang University Affiliated Hospital. 2020. ClinicalTrials.gov Identifier: NCT04270461
(wang2020recentadvancesin pages 13-15): Jian Wang, Cun-Di Li, and Lin Sun. Recent advances in molecular mechanisms of the nkg2d pathway in hepatocellular carcinoma. Biomolecules, 10:301, Feb 2020. URL: https://doi.org/10.3390/biom10020301, doi:10.3390/biom10020301. This article has 28 citations.
(wensveen2018nkg2damaster pages 3-5): Felix M. Wensveen, Vedrana Jelenčić, and Bojan Polić. Nkg2d: a master regulator of immune cell responsiveness. Frontiers in Immunology, Mar 2018. URL: https://doi.org/10.3389/fimmu.2018.00441, doi:10.3389/fimmu.2018.00441. This article has 341 citations and is from a peer-reviewed journal.
(colonna2023thebiologyof pages 11-12): Marco Colonna. The biology of trem receptors. Nature Reviews. Immunology, 23:1-15, Feb 2023. URL: https://doi.org/10.1038/s41577-023-00837-1, doi:10.1038/s41577-023-00837-1. This article has 393 citations.
(wensveen2018nkg2damaster media 312ce8d9): Felix M. Wensveen, Vedrana Jelenčić, and Bojan Polić. Nkg2d: a master regulator of immune cell responsiveness. Frontiers in Immunology, Mar 2018. URL: https://doi.org/10.3389/fimmu.2018.00441, doi:10.3389/fimmu.2018.00441. This article has 341 citations and is from a peer-reviewed journal.
(wensveen2018nkg2damaster media a911c037): Felix M. Wensveen, Vedrana Jelenčić, and Bojan Polić. Nkg2d: a master regulator of immune cell responsiveness. Frontiers in Immunology, Mar 2018. URL: https://doi.org/10.3389/fimmu.2018.00441, doi:10.3389/fimmu.2018.00441. This article has 341 citations and is from a peer-reviewed journal.
(wang2020recentadvancesin pages 5-7): Jian Wang, Cun-Di Li, and Lin Sun. Recent advances in molecular mechanisms of the nkg2d pathway in hepatocellular carcinoma. Biomolecules, 10:301, Feb 2020. URL: https://doi.org/10.3390/biom10020301, doi:10.3390/biom10020301. This article has 28 citations.
(fasbender2016nkcellregulation pages 11-14): Frank Oliver Fasbender. Nk cell regulation. ArXiv, Jan 2016. URL: https://doi.org/10.17877/de290r-18112, doi:10.17877/de290r-18112. This article has 0 citations.
(boneva2025aconcisereview pages 10-11): Elitsa Boneva, Velizar Shivarov, and Milena Ivanova. A concise review of the role of the nkg2d receptor and its ligands in cancer. Immuno, 5:9, Mar 2025. URL: https://doi.org/10.3390/immuno5010009, doi:10.3390/immuno5010009. This article has 14 citations.
id: Q9UBK5
gene_symbol: HCST
product_type: PROTEIN
status: COMPLETE
taxon:
id: NCBITaxon:9606
label: Homo sapiens
description: >-
HCST encodes DAP10/KAP10, a small single-pass transmembrane adaptor that forms
activating receptor complexes with NKG2D/KLRK1 and additional immune
receptors such as CD300H. Its cytoplasmic YINM motif is phosphorylated after
receptor engagement and recruits PI3K p85 and Grb2-Vav1 signaling modules,
promoting PI3K-Akt signaling, calcium mobilization, cytotoxic lymphocyte
activation, and natural killer cell mediated cytotoxicity. HCST is an adaptor
and substrate for phosphorylation, not a kinase.
alternative_products:
- name: '1'
id: Q9UBK5-1
- name: '2'
id: Q9UBK5-2
sequence_note: VSP_033022
existing_annotations:
- term:
id: GO:0051897
label: positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
qualifier: involved_in
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: >-
HCST/DAP10 positively regulates PI3K-Akt signaling by recruiting PI3K
p85 after phosphorylation of its cytoplasmic YINM motif.
action: ACCEPT
reason: >-
This is a core pathway output of DAP10-dependent receptor signaling and
is supported by both the founding DAP10 studies and the falcon review.
supported_by:
- reference_id: file:human/HCST/HCST-deep-research-falcon.md
supporting_text: >-
DAP10 contains a cytoplasmic YINM (YxxM-type) motif that is
phosphorylated after receptor engagement.
- term:
id: GO:0005102
label: signaling receptor binding
qualifier: enables
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: >-
HCST/DAP10 binds signaling receptors, most prominently human NKG2D/KLRK1,
through transmembrane charged-residue interactions.
action: ACCEPT
reason: >-
Signaling receptor binding is a direct molecular role of HCST in
NKG2D-DAP10 receptor complex assembly.
supported_by:
- reference_id: file:human/HCST/HCST-deep-research-falcon.md
supporting_text: >-
NKG2D recruits its adaptor through charged residue complementarity
in the transmembrane region.
- term:
id: GO:0043548
label: phosphatidylinositol 3-kinase binding
qualifier: enables
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: >-
PI3K binding is a direct DAP10 molecular function mediated by the
phosphorylated YINM/YxxM motif.
action: ACCEPT
reason: >-
This is a specific, experimentally supported part of the HCST signaling
adaptor mechanism.
supported_by:
- reference_id: PMID:10528161
supporting_text: >-
KAP10, unlike other transmembrane adapter proteins, binds
phosphatidylinositol-3 kinase following phosphorylation of a
cytoplasmic YINM motif, which results in activation of Akt.
- term:
id: GO:0005102
label: signaling receptor binding
qualifier: enables
evidence_type: IEA
original_reference_id: GO_REF:0000002
review:
summary: >-
The InterPro-derived signaling receptor binding annotation is consistent
with direct experimental evidence for NKG2D and CD300H association.
action: ACCEPT
reason: >-
HCST is a transmembrane adaptor whose receptor association is a core
molecular feature.
supported_by:
- reference_id: PMID:15294961
supporting_text: >-
DAP10 is sufficient for human NKG2D signal transduction.
- term:
id: GO:0016020
label: membrane
qualifier: located_in
evidence_type: IEA
original_reference_id: GO_REF:0000120
review:
summary: >-
HCST is membrane-localized, but the broad membrane term should be
replaced by the more specific plasma membrane annotation already
supported experimentally.
action: MODIFY
reason: >-
HCST is a single-pass membrane protein that functions in cell-surface
immune receptor complexes.
proposed_replacement_terms:
- id: GO:0005886
label: plasma membrane
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
In natural killer (NK) and T cells, DAP10 was identified as a cell
surface adaptor protein in an activating receptor complex with
NKG2D.
- term:
id: GO:0043548
label: phosphatidylinositol 3-kinase binding
qualifier: enables
evidence_type: IEA
original_reference_id: GO_REF:0000002
review:
summary: >-
The family-based PI3K binding annotation is supported by direct DAP10
biochemical studies.
action: ACCEPT
reason: >-
PI3K binding through the phosphorylated YINM motif is central to HCST
function.
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
Within the DAP10 cytoplasmic domain, an Src homology 2 (SH2)
domain-binding site was capable of recruiting the p85 subunit of the
phosphatidylinositol 3-kinase (PI 3-kinase).
- term:
id: GO:0050776
label: regulation of immune response
qualifier: involved_in
evidence_type: IEA
original_reference_id: GO_REF:0000002
review:
summary: >-
This broad immune-response annotation is directionally correct but less
useful than the specific NK-cell cytotoxicity and PI3K-Akt signaling
annotations.
action: MODIFY
reason: >-
HCST's best-supported immune process is DAP10-dependent activation of
cytotoxic lymphocyte responses, including natural killer cell mediated
cytotoxicity.
proposed_replacement_terms:
- id: GO:0042267
label: natural killer cell mediated cytotoxicity
supported_by:
- reference_id: PMID:16582911
supporting_text: >-
For full calcium release and cytotoxicity to occur, both Grb2-Vav1
and p85 had to bind to DAP10.
- term:
id: GO:0051897
label: positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
qualifier: involved_in
evidence_type: IEA
original_reference_id: GO_REF:0000002
review:
summary: >-
The InterPro-derived PI3K-Akt pathway annotation matches the established
DAP10 YINM motif mechanism.
action: ACCEPT
reason: >-
DAP10 recruits PI3K p85 and activates Akt downstream of receptor
engagement.
supported_by:
- reference_id: PMID:10528161
supporting_text: >-
binds phosphatidylinositol-3 kinase following phosphorylation of a
cytoplasmic YINM motif, which results in activation of Akt.
- term:
id: GO:0005515
label: protein binding
qualifier: enables
evidence_type: IPI
original_reference_id: PMID:32296183
review:
summary: >-
The HuRI protein-binding hits are large-scale binary interactome data
and do not define HCST's specific immune-receptor adaptor function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
Protein binding is too generic and the listed high-throughput partners
are not part of the established NKG2D/DAP10 or CD300H/DAP10 signaling
mechanism.
supported_by:
- reference_id: PMID:32296183
supporting_text: >-
Here we present a human 'all-by-all' reference interactome map of
human binary protein interactions, or 'HuRI'.
- term:
id: GO:0005515
label: protein binding
qualifier: enables
evidence_type: IPI
original_reference_id: PMID:32814053
review:
summary: >-
This neurodegenerative-disease interactome protein-binding annotation is
not sufficient to define a core HCST function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
The established function of HCST is immune receptor adaptor signaling;
a generic high-throughput protein-binding annotation to a
neurodegeneration interactome partner should not be treated as core
function.
supported_by:
- reference_id: PMID:32814053
supporting_text: >-
Interactome maps are valuable resources to elucidate protein
function and disease mechanisms.
- term:
id: GO:0005886
label: plasma membrane
qualifier: is_active_in
evidence_type: IDA
original_reference_id: PMID:15894612
review:
summary: >-
HCST/DAP10 acts in a plasma-membrane NKG2D receptor complex.
action: ACCEPT
reason: >-
The NKG2D-DAP10 hexameric signaling complex assembles in the membrane,
and HCST is a single-pass membrane adaptor.
supported_by:
- reference_id: PMID:15894612
supporting_text: >-
The human receptor assembles with the DAP10 signaling dimer.
- term:
id: GO:0030674
label: protein-macromolecule adaptor activity
qualifier: enables
evidence_type: IDA
original_reference_id: PMID:16582911
review:
summary: >-
The adaptor annotation is correct but can be made more specific:
HCST/DAP10 is a signaling receptor complex adaptor.
action: MODIFY
reason: >-
DAP10 links ligand-binding receptors to PI3K and Grb2-Vav1 signaling
modules, which is specifically signaling receptor complex adaptor
activity.
proposed_replacement_terms:
- id: GO:0030159
label: signaling receptor complex adaptor activity
supported_by:
- reference_id: PMID:16582911
supporting_text: >-
Human natural killer cells express NKG2D and require the
transmembrane adaptor DAP10 to initiate their full cytotoxic
activation.
- reference_id: file:human/HCST/HCST-deep-research-falcon.md
supporting_text: >-
HCST/DAP10 is a membrane adaptor required for NKG2D signal
transduction because NKG2D has a short cytoplasmic tail lacking
intrinsic signaling motifs.
- term:
id: GO:0042267
label: natural killer cell mediated cytotoxicity
qualifier: involved_in
evidence_type: IDA
original_reference_id: PMID:16582911
review:
summary: >-
DAP10-dependent NKG2D signaling is required for full human NK-cell
cytotoxic activation.
action: ACCEPT
reason: >-
This is a core biological process for HCST in cytotoxic lymphocyte
receptor signaling.
supported_by:
- reference_id: PMID:16582911
supporting_text: >-
For full calcium release and cytotoxicity to occur, both Grb2-Vav1
and p85 had to bind to DAP10.
- term:
id: GO:0005515
label: protein binding
qualifier: enables
evidence_type: IPI
original_reference_id: PMID:26221034
review:
summary: >-
HCST/DAP10 association with CD300H is a receptor-adaptor interaction, so
the generic protein binding term should be replaced by signaling
receptor binding.
action: MODIFY
reason: >-
CD300H is an immunoreceptor that associates with DAP10; the informative
functional description is receptor binding/adaptor signaling rather than
generic protein binding.
proposed_replacement_terms:
- id: GO:0005102
label: signaling receptor binding
supported_by:
- reference_id: PMID:26221034
supporting_text: >-
CD300H has a short cytoplasmic tail and associates with the
signaling adaptor proteins, DAP12 and DAP10.
- term:
id: GO:0005102
label: signaling receptor binding
qualifier: enables
evidence_type: IPI
original_reference_id: PMID:15294961
review:
summary: >-
Human NKG2D uses DAP10/HCST for signal transduction rather than DAP12.
action: ACCEPT
reason: >-
This directly supports HCST binding a signaling receptor in the human
NKG2D pathway.
supported_by:
- reference_id: PMID:15294961
supporting_text: >-
human NKG2D is incapable of associating with DAP12 and provide
evidence that structural differences in the transmembrane of mouse
and human NKG2D account for the species-specific difference for this
immune receptor.
- term:
id: GO:0009986
label: cell surface
qualifier: located_in
evidence_type: IDA
original_reference_id: PMID:15294961
review:
summary: >-
HCST/DAP10 functions at the cell surface as part of NKG2D receptor
complexes.
action: ACCEPT
reason: >-
Cell-surface localization is consistent with DAP10-dependent
receptor-complex assembly and signaling.
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
DAP10 was identified as a cell surface adaptor protein in an
activating receptor complex with NKG2D.
- term:
id: GO:0005886
label: plasma membrane
qualifier: located_in
evidence_type: TAS
original_reference_id: Reactome:R-HSA-198983
review:
summary: >-
The Reactome annotation to plasma membrane is consistent with the
NKG2D-DAP10 receptor complex acting at the cell surface.
action: ACCEPT
reason: >-
HCST is a single-pass transmembrane adaptor in an activating immune
receptor complex.
supported_by:
- reference_id: Reactome:R-HSA-198983
supporting_text: >-
NKG2D is an activating immunoreceptor.
- term:
id: GO:0005515
label: protein binding
qualifier: enables
evidence_type: IPI
original_reference_id: PMID:10426994
review:
summary: >-
The NKG2D-DAP10 interaction is real, but it should be represented as
signaling receptor binding rather than generic protein binding.
action: MODIFY
reason: >-
HCST/DAP10 binds the NKG2D signaling receptor in a functional receptor
complex.
proposed_replacement_terms:
- id: GO:0005102
label: signaling receptor binding
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
DAP10 was identified as a cell surface adaptor protein in an
activating receptor complex with NKG2D.
- term:
id: GO:0009986
label: cell surface
qualifier: located_in
evidence_type: IDA
original_reference_id: PMID:10426994
review:
summary: >-
HCST/DAP10 is a cell-surface adaptor in the activating NKG2D receptor
complex.
action: ACCEPT
reason: >-
Cell surface is an experimentally supported location for the DAP10
receptor complex.
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
DAP10 was identified as a cell surface adaptor protein in an
activating receptor complex with NKG2D.
- term:
id: GO:0043548
label: phosphatidylinositol 3-kinase binding
qualifier: enables
evidence_type: IDA
original_reference_id: PMID:10426994
review:
summary: >-
Direct founding evidence supports recruitment of PI3K p85 by DAP10.
action: ACCEPT
reason: >-
PI3K binding is an experimentally supported molecular function of the
phosphorylated DAP10 cytoplasmic motif.
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
an Src homology 2 (SH2) domain-binding site was capable of
recruiting the p85 subunit of the phosphatidylinositol 3-kinase (PI
3-kinase).
- term:
id: GO:0051897
label: positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
qualifier: involved_in
evidence_type: IDA
original_reference_id: PMID:10426994
review:
summary: >-
NKG2D-DAP10 signaling activates PI3K and downstream Akt signaling.
action: ACCEPT
reason: >-
This process is a core signaling output of HCST/DAP10.
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
providing for NKG2D-dependent signal transduction.
- reference_id: PMID:10528161
supporting_text: >-
binds phosphatidylinositol-3 kinase following phosphorylation of a
cytoplasmic YINM motif, which results in activation of Akt.
- term:
id: GO:0006468
label: protein phosphorylation
qualifier: involved_in
evidence_type: IGI
original_reference_id: PMID:10528161
review:
summary: >-
The cited biology is HCST/DAP10-mediated PI3K-Akt activation after
phosphorylation of the DAP10 YINM motif; the broad protein
phosphorylation process term should be replaced by the specific
PI3K-Akt signaling term.
action: MODIFY
reason: >-
HCST is phosphorylated as part of receptor signaling and then recruits
PI3K, so the best process-level annotation is positive regulation of
PI3K/protein kinase B signal transduction, not the broad protein
phosphorylation process.
proposed_replacement_terms:
- id: GO:0051897
label: positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
supported_by:
- reference_id: PMID:10528161
supporting_text: >-
binds phosphatidylinositol-3 kinase following phosphorylation of a
cytoplasmic YINM motif, which results in activation of Akt.
references:
- id: GO_REF:0000002
title: Gene Ontology annotation through association of InterPro records with GO terms
findings: []
- id: GO_REF:0000033
title: Annotation inferences using phylogenetic trees
findings: []
- id: GO_REF:0000120
title: Combined Automated Annotation using Multiple IEA Methods
findings: []
- id: PMID:10426994
title: An activating immunoreceptor complex formed by NKG2D and DAP10.
findings: []
- id: PMID:10528161
title: 'Cutting edge: KAP10, a novel transmembrane adapter protein genetically linked to DAP12 but with unique signaling properties.'
findings: []
- id: PMID:15294961
title: A Structural basis for the association of DAP12 with mouse, but not human, NKG2D.
findings: []
- id: PMID:15894612
title: The activating NKG2D receptor assembles in the membrane with two signaling dimers into a hexameric structure.
findings: []
- id: PMID:16582911
title: NKG2D-mediated signaling requires a DAP10-bound Grb2-Vav1 intermediate and phosphatidylinositol-3-kinase in human natural killer cells.
findings: []
- id: PMID:26221034
title: Identification and Characterization of CD300H, a New Member of the Human CD300 Immunoreceptor Family.
findings: []
- id: PMID:32296183
title: A reference map of the human binary protein interactome.
findings: []
- id: PMID:32814053
title: Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains.
findings: []
- id: Reactome:R-HSA-198983
title: NKG2D homodimer interacting with ligands
findings: []
- id: file:human/HCST/HCST-deep-research-falcon.md
title: Falcon deep research report for human HCST
findings: []
core_functions:
- description: >-
Cell-surface signaling receptor complex adaptor for human NKG2D/KLRK1 and
related immune receptors, coupling ligand recognition to PI3K-Akt and
Grb2-Vav1 pathways that enable full natural killer cell cytotoxic
activation.
molecular_function:
id: GO:0030159
label: signaling receptor complex adaptor activity
directly_involved_in:
- id: GO:0051897
label: positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction
- id: GO:0042267
label: natural killer cell mediated cytotoxicity
locations:
- id: GO:0005886
label: plasma membrane
- id: GO:0009986
label: cell surface
supported_by:
- reference_id: PMID:10426994
supporting_text: >-
DAP10 was identified as a cell surface adaptor protein in an
activating receptor complex with NKG2D.
- reference_id: PMID:16582911
supporting_text: >-
Human natural killer cells express NKG2D and require the
transmembrane adaptor DAP10 to initiate their full cytotoxic
activation.
- reference_id: file:human/HCST/HCST-deep-research-falcon.md
supporting_text: >-
HCST/DAP10 is a membrane adaptor required for NKG2D signal
transduction because NKG2D has a short cytoplasmic tail lacking
intrinsic signaling motifs.
proposed_new_terms: []
suggested_questions:
- question: Which non-NKG2D human receptors use HCST/DAP10 as a physiologically important adaptor in primary immune cells?
- question: Does HCST's Grb2-Vav1 branch or PI3K branch dominate cytotoxicity, cytokine production, and survival in different human NK and T-cell contexts?
- question: Are the high-throughput HCST interactors outside the NKG2D/CD300H receptor-signaling context reproducible at endogenous protein levels?
suggested_experiments:
- description: CRISPR knockout and rescue of HCST in primary human NK cells using wild-type, YINM-mutant, PI3K-binding-defective, and Grb2-binding-defective DAP10 variants.
experiment_type: cell-based functional assay
hypothesis: Both PI3K p85 and Grb2-Vav1 recruitment to HCST are required for full NKG2D-dependent cytotoxicity.
- description: Endogenous co-immunoprecipitation of HCST with KLRK1 and CD300H in primary NK cells, monocytes, and myeloid dendritic cells after receptor ligation.
experiment_type: protein interaction assay
hypothesis: HCST receptor-adaptor partnerships are cell-type restricted and distinguish core NKG2D signaling from non-core interactome hits.
- description: Phosphoproteomic time course after NKG2D engagement in control and HCST-deficient human NK cells.
experiment_type: phosphoproteomics
hypothesis: HCST is required upstream of PI3K-Akt, Grb2-Vav1, calcium mobilization, and cytotoxicity-associated phosphorylation programs.