{"gene":"HSPH1","run_date":"2026-06-10T01:55:22","timeline":{"discoveries":[{"year":2015,"finding":"HSPH1 physically interacts with the oncoproteins c-Myc and Bcl-6 in aggressive B-cell non-Hodgkin lymphoma cells and primary tumors, and HSPH1 silencing leads to downregulation of both proteins, growth delay, and loss of tumorigenicity, indicating HSPH1 stabilizes these key oncoproteins as a chaperone client interaction.","method":"Co-immunoprecipitation (Co-IP) in Namalwa cells and primary B-NHL samples; shRNA-mediated HSPH1 silencing with in vitro and in vivo tumor growth assays","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus in vivo functional validation in a single lab with two orthogonal methods","pmids":["25573990"],"is_preprint":false},{"year":2020,"finding":"HSPH1 interacts with STAT3 and enhances its phosphorylation in alveolar macrophages; this is downstream of a KLF2-mediated transcriptional suppression pathway in which IL-1β downregulates KLF2, thereby de-repressing HSPH1 expression and promoting STAT3 activation and MMP-2/9 upregulation in LPS-induced acute lung injury.","method":"Co-immunoprecipitation (HSPH1–STAT3 interaction); KLF2 overexpression/knockdown; IL-1R1 knockdown; HSPH1 inhibitor treatment in rat ALI model; Western blot for p-STAT3","journal":"Bioscience reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus genetic and pharmacological interventions in cell and animal models, single lab","pmids":["32091104"],"is_preprint":false},{"year":2024,"finding":"YTHDF1 (an m6A reader protein) binds HSPH1 mRNA and promotes its translation; YTHDF1 knockdown suppresses HSPH1 protein but not RNA levels, placing YTHDF1 as a translational regulator of HSPH1 in gastric carcinogenesis.","method":"RNA immunoprecipitation (RIP-qPCR) for YTHDF1–HSPH1 mRNA interaction; Western blot showing protein-specific suppression without RNA change upon YTHDF1 knockdown; RNA-seq and proteomics","journal":"Cell proliferation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP-qPCR plus orthogonal protein/RNA level measurements, single lab","pmids":["38444279"],"is_preprint":false},{"year":2023,"finding":"Human HSPH1/HSP110 functions as a molecular chaperone capable of protecting against protein aggregation and, together with HSP70/HSP40, refolding and disaggregating substrate proteins; small-angle X-ray scattering characterization showed an elongated conformation similar to plant SbHSP110.","method":"In vitro chaperone activity assays (aggregation protection, refolding, reactivation); small-angle X-ray scattering (SAXS); spectroscopic and hydrodynamic characterization of purified recombinant protein","journal":"Biopolymers","confidence":"High","confidence_rationale":"Tier 1 / Moderate — direct in vitro reconstitution of chaperone activities with structural (SAXS) characterization, multiple orthogonal biophysical methods in a single study","pmids":["36825649"],"is_preprint":false},{"year":2025,"finding":"Transcription factor Sp2 directly binds the Hsph1 gene promoter and promotes its transcription; the Sp2/HSPH1 signaling axis mediates acrylamide-induced oxidative stress, apoptosis, and autophagy in mouse spermatogonial stem cells (C18-4 cells).","method":"Promoter binding assay (Sp2 binding to Hsph1 promoter); Sp2/HSPH1 knockdown and overexpression; apoptosis and autophagy readouts; ROS measurement","journal":"Free radical biology & medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — transcription factor–promoter binding with functional genetic validation in a single lab, single study","pmids":["40972724"],"is_preprint":false},{"year":2026,"finding":"HSPH1 interacts physically with DNAJB1 (HSP40) and the two proteins co-localize in the cytosol under hepatic ischemia-reperfusion injury conditions; both are upregulated, and together they are implicated in maintaining protein homeostasis during cellular stress.","method":"Co-immunoprecipitation (Co-IP); immunofluorescence co-localization; Western blot and qPCR in mouse IRI model, clinical liver transplant tissue, and AML12 cell hypoxia/reoxygenation model","journal":"Molecular immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus co-localization in multiple experimental systems (mouse, human tissue, cell model), single lab","pmids":["41534252"],"is_preprint":false},{"year":2026,"finding":"HSPH1 interacts with HSPA5 (BiP/GRP78) to regulate the endoplasmic reticulum stress pathway; HSPH1 knockdown disrupts ER ultrastructure and promotes apoptosis, while overexpression alleviates OGD/R-induced cell damage, demonstrating that HSPH1 maintains ER homeostasis and inhibits excessive ERS-driven apoptosis in cardiomyocytes.","method":"Co-immunoprecipitation (Co-IP) of HSPH1–HSPA5; HSPH1 knockdown/overexpression; transmission electron microscopy of ER ultrastructure; Western blot of ERS markers; flow cytometry for apoptosis; rescue experiments","journal":"Folia morphologica","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus multiple orthogonal cellular assays and rescue experiments, single lab","pmids":["41925682"],"is_preprint":false}],"current_model":"HSPH1 (HSP110/HSP105) is a large ATP-binding molecular chaperone that, together with HSP70 and HSP40 partners (including HSPA5/BiP and DNAJB1), prevents protein aggregation and facilitates refolding/disaggregation of misfolded substrates; it also stabilizes oncoprotein clients (c-Myc, Bcl-6) through direct physical interaction, enhances STAT3 phosphorylation via a direct interaction with STAT3, maintains ER homeostasis through interaction with HSPA5, and is transcriptionally regulated by Sp2 and translationally regulated by the m6A reader YTHDF1."},"narrative":{"mechanistic_narrative":"HSPH1 (HSP110/HSP105) is a large ATP-binding molecular chaperone that protects proteins from aggregation and, in concert with the HSP70/HSP40 system, refolds and disaggregates misfolded substrates [PMID:36825649]. Direct in vitro reconstitution established its core chaperone activities and revealed an elongated conformation by SAXS [PMID:36825649], and it physically partners with the HSP40 co-chaperone DNAJB1 in the cytosol during cellular stress [PMID:41534252] and with HSPA5/BiP to maintain endoplasmic reticulum homeostasis and restrain ER stress-driven apoptosis [PMID:41925682]. Beyond generic proteostasis, HSPH1 stabilizes oncogenic clients: it physically binds c-Myc and Bcl-6 in aggressive B-cell lymphoma, with its silencing collapsing both proteins and abolishing tumorigenicity [PMID:25573990], and it interacts with STAT3 to enhance STAT3 phosphorylation in inflammatory lung injury [PMID:32091104]. HSPH1 expression is controlled at multiple levels — transcriptionally through direct promoter binding by Sp2 in an oxidative-stress/apoptosis axis [PMID:40972724] and translationally through the m6A reader YTHDF1, which binds HSPH1 mRNA to promote its translation [PMID:38444279].","teleology":[{"year":2015,"claim":"Established that HSPH1 acts as a client-stabilizing chaperone for specific oncoproteins rather than only as a general housekeeping chaperone, linking it to lymphoma maintenance.","evidence":"Reciprocal Co-IP plus shRNA silencing with in vitro and in vivo tumor growth assays in B-NHL cells and primary tumors","pmids":["25573990"],"confidence":"Medium","gaps":["Direct chaperone binding versus indirect stabilization of c-Myc/Bcl-6 not structurally resolved","ATPase dependence of the client interaction untested","Single lab"]},{"year":2020,"claim":"Connected HSPH1 to inflammatory signal transduction by showing it binds STAT3 and promotes its phosphorylation downstream of KLF2 de-repression.","evidence":"Co-IP of HSPH1–STAT3, KLF2 and IL-1R1 perturbations, and HSPH1 inhibitor treatment in a rat acute lung injury model","pmids":["32091104"],"confidence":"Medium","gaps":["Mechanism by which HSPH1 enhances STAT3 phosphorylation (direct vs. scaffolding) unresolved","Whether interaction requires chaperone activity not addressed"]},{"year":2023,"claim":"Defined the biochemical and structural basis of human HSPH1 function by directly reconstituting its anti-aggregation, refolding and disaggregation activities and resolving its elongated conformation.","evidence":"In vitro chaperone assays with purified recombinant protein, SAXS, and biophysical characterization","pmids":["36825649"],"confidence":"High","gaps":["High-resolution structure of substrate-bound state not determined","Cellular substrate repertoire not defined in this study"]},{"year":2024,"claim":"Identified a translational control layer for HSPH1, showing the m6A reader YTHDF1 binds its mRNA to boost protein output independent of transcript level.","evidence":"RIP-qPCR for YTHDF1–HSPH1 mRNA binding plus protein/RNA level measurements and omics in gastric carcinogenesis","pmids":["38444279"],"confidence":"Medium","gaps":["m6A sites on HSPH1 mRNA not mapped","Functional consequence of elevated HSPH1 for the tumor phenotype not isolated from broader YTHDF1 effects"]},{"year":2025,"claim":"Established transcriptional regulation of HSPH1 by Sp2 and placed the Sp2/HSPH1 axis in oxidative-stress-driven apoptosis and autophagy.","evidence":"Sp2–promoter binding assay with knockdown/overexpression and ROS/apoptosis/autophagy readouts in mouse spermatogonial stem cells","pmids":["40972724"],"confidence":"Medium","gaps":["Single study and single cell model","Direct molecular role of HSPH1 protein downstream of Sp2 not mechanistically dissected"]},{"year":2026,"claim":"Anchored HSPH1 within the canonical HSP40 co-chaperone partnership and ER chaperone machinery, supporting its role in stress proteostasis.","evidence":"Co-IP and immunofluorescence co-localization of HSPH1–DNAJB1 in hepatic IRI models, and Co-IP of HSPH1–HSPA5 with ER ultrastructure, ERS markers and rescue experiments in cardiomyocytes","pmids":["41534252","41925682"],"confidence":"Medium","gaps":["Whether HSPH1–DNAJB1 and HSPH1–HSPA5 form defined stoichiometric complexes not established","ATPase/nucleotide-exchange cycle linking these interactions to substrate handling untested","Single lab per interaction"]},{"year":null,"claim":"The cellular substrate spectrum of HSPH1 and how its nucleotide-bound states couple to client stabilization, ER homeostasis and oncoprotein maintenance remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unbiased substrate/interactome map in the corpus","No structure of HSPH1 bound to a defined client or co-chaperone","Mechanistic link between chaperone cycle and oncoprotein/STAT3 effects unestablished"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140657","term_label":"ATP-dependent activity","supporting_discovery_ids":[3]},{"term_id":"GO:0044183","term_label":"protein folding chaperone","supporting_discovery_ids":[3,5,6]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[5]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[6]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[3,5,6]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[4,6]}],"complexes":[],"partners":["DNAJB1","HSPA5","STAT3","MYC","BCL6","YTHDF1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q92598","full_name":"Heat shock protein 105 kDa","aliases":["Antigen NY-CO-25","Heat shock 110 kDa protein","Heat shock protein family H member 1"],"length_aa":858,"mass_kda":96.9,"function":"Acts as a nucleotide-exchange factor (NEF) for chaperone proteins HSPA1A and HSPA1B, promoting the release of ADP from HSPA1A/B thereby triggering client/substrate protein release (PubMed:24318877). Prevents the aggregation of denatured proteins in cells under severe stress, on which the ATP levels decrease markedly. Inhibits HSPA8/HSC70 ATPase and chaperone activities (By similarity)","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q92598/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/HSPH1","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000120694","cell_line_id":"CID000053","localizations":[{"compartment":"cytoplasmic","grade":3},{"compartment":"nucleoplasm","grade":2},{"compartment":"nuclear_punctae","grade":1}],"interactors":[{"gene":"DNAJB1","stoichiometry":10.0},{"gene":"HSPA8","stoichiometry":10.0},{"gene":"HSPA5","stoichiometry":4.0},{"gene":"ATG9A","stoichiometry":0.2},{"gene":"BTF3","stoichiometry":0.2},{"gene":"CLTA","stoichiometry":0.2},{"gene":"DNAJA1","stoichiometry":0.2},{"gene":"DNAJB4","stoichiometry":0.2},{"gene":"DNAJB6","stoichiometry":0.2},{"gene":"DNAJC8","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000053","total_profiled":1310},"omim":[{"mim_id":"614908","title":"HEAT SHOCK PROTEIN NUCLEAR IMPORT FACTOR HIKESHI; HIKESHI","url":"https://www.omim.org/entry/614908"},{"mim_id":"610703","title":"HEAT-SHOCK 105/110-KD PROTEIN 1; HSPH1","url":"https://www.omim.org/entry/610703"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Cytosol","reliability":"Enhanced"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/HSPH1"},"hgnc":{"alias_symbol":["HSP105B","KIAA0201","HSP105A","NY-CO-25"],"prev_symbol":[]},"alphafold":{"accession":"Q92598","domains":[{"cath_id":"3.30.420.40","chopping":"3-232_312-393","consensus_level":"medium","plddt":96.4421,"start":3,"end":393},{"cath_id":"3.90.640.10","chopping":"233-311","consensus_level":"medium","plddt":96.7516,"start":233,"end":311},{"cath_id":"2.60.34.10","chopping":"400-501","consensus_level":"high","plddt":91.6333,"start":400,"end":501},{"cath_id":"1.20.1270.10","chopping":"624-694","consensus_level":"medium","plddt":95.147,"start":624,"end":694},{"cath_id":"1.20.1270","chopping":"705-800","consensus_level":"medium","plddt":91.6018,"start":705,"end":800}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q92598","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q92598-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q92598-F1-predicted_aligned_error_v6.png","plddt_mean":85.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=HSPH1","jax_strain_url":"https://www.jax.org/strain/search?query=HSPH1"},"sequence":{"accession":"Q92598","fasta_url":"https://rest.uniprot.org/uniprotkb/Q92598.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q92598/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q92598"}},"corpus_meta":[{"pmid":"9039502","id":"PMC_9039502","title":"Prediction of the coding sequences of unidentified human genes. VI. The coding sequences of 80 new genes (KIAA0201-KIAA0280) deduced by analysis of cDNA clones from cell line KG-1 and brain.","date":"1996","source":"DNA research : an international journal for rapid publication of reports on genes and genomes","url":"https://pubmed.ncbi.nlm.nih.gov/9039502","citation_count":178,"is_preprint":false},{"pmid":"25573990","id":"PMC_25573990","title":"HSPH1 inhibition downregulates Bcl-6 and c-Myc and hampers the growth of human aggressive B-cell non-Hodgkin lymphoma.","date":"2015","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/25573990","citation_count":50,"is_preprint":false},{"pmid":"32091104","id":"PMC_32091104","title":"Activation of the IL-1β/KLF2/HSPH1 pathway promotes STAT3 phosphorylation in alveolar macrophages during LPS-induced acute lung injury.","date":"2020","source":"Bioscience reports","url":"https://pubmed.ncbi.nlm.nih.gov/32091104","citation_count":26,"is_preprint":false},{"pmid":"32815538","id":"PMC_32815538","title":"Oncogene HSPH1 modulated by the rs2280059 genetic variant diminishes EGFR-TKIs efficiency in advanced lung adenocarcinoma.","date":"2020","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/32815538","citation_count":16,"is_preprint":false},{"pmid":"38444279","id":"PMC_38444279","title":"YTHDF1 mediates N-methyl-N-nitrosourea-induced gastric carcinogenesis by controlling HSPH1 translation.","date":"2024","source":"Cell proliferation","url":"https://pubmed.ncbi.nlm.nih.gov/38444279","citation_count":13,"is_preprint":false},{"pmid":"38165608","id":"PMC_38165608","title":"Extracellular vesicles related gene HSPH1 exerts anti-tumor effects in prostate cancer via promoting the stress response of CD8 + T cells.","date":"2024","source":"Cellular oncology (Dordrecht, Netherlands)","url":"https://pubmed.ncbi.nlm.nih.gov/38165608","citation_count":7,"is_preprint":false},{"pmid":"40972724","id":"PMC_40972724","title":"HSPH1 is essential for acrylamide-induced apoptosis and autophagy of mouse spermatogonial stem cells.","date":"2025","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40972724","citation_count":0,"is_preprint":false},{"pmid":"36825649","id":"PMC_36825649","title":"Sorghum bicolor SbHSP110 has an elongated shape and is able of protecting against aggregation and replacing human HSPH1/HSP110 in refolding and disaggregation assays.","date":"2023","source":"Biopolymers","url":"https://pubmed.ncbi.nlm.nih.gov/36825649","citation_count":0,"is_preprint":false},{"pmid":"42108450","id":"PMC_42108450","title":"Single-cell and bulk omics uncover fibroblast heterogeneity and HSPH1 as a key driver in Barrett's esophagus to esophageal adenocarcinoma progression.","date":"2026","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/42108450","citation_count":0,"is_preprint":false},{"pmid":"41534252","id":"PMC_41534252","title":"HSPH1 and DNAJB1 as potential key regulators in hepatic ischemia-reperfusion injury.","date":"2026","source":"Molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/41534252","citation_count":0,"is_preprint":false},{"pmid":"41925682","id":"PMC_41925682","title":"Hsph1 alleviates hypoxia-glucose deprivation-induced cardiomyocyte damage by regulating endoplasmic reticulum stress.","date":"2026","source":"Folia morphologica","url":"https://pubmed.ncbi.nlm.nih.gov/41925682","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.07.23.604777","title":"SARS-CoV-2 S, M and E Structural Proteins Down-modulate HIV-1 LTR Activity and Modulate Endoplasmic Reticulum Stress Responses","date":"2024-07-23","source":"bioRxiv","url":"https://doi.org/10.1101/2024.07.23.604777","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8686,"output_tokens":1937,"usd":0.027557,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8848,"output_tokens":2544,"usd":0.05392,"stage2_stop_reason":"end_turn"},"total_usd":0.081477,"stage1_batch_id":"msgbatch_01DUPACZi7AAWwuZiUjseQF4","stage2_batch_id":"msgbatch_018yt7chE3f48PEFtDwtj6AE","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2015,\n      \"finding\": \"HSPH1 physically interacts with the oncoproteins c-Myc and Bcl-6 in aggressive B-cell non-Hodgkin lymphoma cells and primary tumors, and HSPH1 silencing leads to downregulation of both proteins, growth delay, and loss of tumorigenicity, indicating HSPH1 stabilizes these key oncoproteins as a chaperone client interaction.\",\n      \"method\": \"Co-immunoprecipitation (Co-IP) in Namalwa cells and primary B-NHL samples; shRNA-mediated HSPH1 silencing with in vitro and in vivo tumor growth assays\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus in vivo functional validation in a single lab with two orthogonal methods\",\n      \"pmids\": [\"25573990\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"HSPH1 interacts with STAT3 and enhances its phosphorylation in alveolar macrophages; this is downstream of a KLF2-mediated transcriptional suppression pathway in which IL-1β downregulates KLF2, thereby de-repressing HSPH1 expression and promoting STAT3 activation and MMP-2/9 upregulation in LPS-induced acute lung injury.\",\n      \"method\": \"Co-immunoprecipitation (HSPH1–STAT3 interaction); KLF2 overexpression/knockdown; IL-1R1 knockdown; HSPH1 inhibitor treatment in rat ALI model; Western blot for p-STAT3\",\n      \"journal\": \"Bioscience reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus genetic and pharmacological interventions in cell and animal models, single lab\",\n      \"pmids\": [\"32091104\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"YTHDF1 (an m6A reader protein) binds HSPH1 mRNA and promotes its translation; YTHDF1 knockdown suppresses HSPH1 protein but not RNA levels, placing YTHDF1 as a translational regulator of HSPH1 in gastric carcinogenesis.\",\n      \"method\": \"RNA immunoprecipitation (RIP-qPCR) for YTHDF1–HSPH1 mRNA interaction; Western blot showing protein-specific suppression without RNA change upon YTHDF1 knockdown; RNA-seq and proteomics\",\n      \"journal\": \"Cell proliferation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP-qPCR plus orthogonal protein/RNA level measurements, single lab\",\n      \"pmids\": [\"38444279\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Human HSPH1/HSP110 functions as a molecular chaperone capable of protecting against protein aggregation and, together with HSP70/HSP40, refolding and disaggregating substrate proteins; small-angle X-ray scattering characterization showed an elongated conformation similar to plant SbHSP110.\",\n      \"method\": \"In vitro chaperone activity assays (aggregation protection, refolding, reactivation); small-angle X-ray scattering (SAXS); spectroscopic and hydrodynamic characterization of purified recombinant protein\",\n      \"journal\": \"Biopolymers\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct in vitro reconstitution of chaperone activities with structural (SAXS) characterization, multiple orthogonal biophysical methods in a single study\",\n      \"pmids\": [\"36825649\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Transcription factor Sp2 directly binds the Hsph1 gene promoter and promotes its transcription; the Sp2/HSPH1 signaling axis mediates acrylamide-induced oxidative stress, apoptosis, and autophagy in mouse spermatogonial stem cells (C18-4 cells).\",\n      \"method\": \"Promoter binding assay (Sp2 binding to Hsph1 promoter); Sp2/HSPH1 knockdown and overexpression; apoptosis and autophagy readouts; ROS measurement\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — transcription factor–promoter binding with functional genetic validation in a single lab, single study\",\n      \"pmids\": [\"40972724\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"HSPH1 interacts physically with DNAJB1 (HSP40) and the two proteins co-localize in the cytosol under hepatic ischemia-reperfusion injury conditions; both are upregulated, and together they are implicated in maintaining protein homeostasis during cellular stress.\",\n      \"method\": \"Co-immunoprecipitation (Co-IP); immunofluorescence co-localization; Western blot and qPCR in mouse IRI model, clinical liver transplant tissue, and AML12 cell hypoxia/reoxygenation model\",\n      \"journal\": \"Molecular immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus co-localization in multiple experimental systems (mouse, human tissue, cell model), single lab\",\n      \"pmids\": [\"41534252\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"HSPH1 interacts with HSPA5 (BiP/GRP78) to regulate the endoplasmic reticulum stress pathway; HSPH1 knockdown disrupts ER ultrastructure and promotes apoptosis, while overexpression alleviates OGD/R-induced cell damage, demonstrating that HSPH1 maintains ER homeostasis and inhibits excessive ERS-driven apoptosis in cardiomyocytes.\",\n      \"method\": \"Co-immunoprecipitation (Co-IP) of HSPH1–HSPA5; HSPH1 knockdown/overexpression; transmission electron microscopy of ER ultrastructure; Western blot of ERS markers; flow cytometry for apoptosis; rescue experiments\",\n      \"journal\": \"Folia morphologica\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus multiple orthogonal cellular assays and rescue experiments, single lab\",\n      \"pmids\": [\"41925682\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"HSPH1 (HSP110/HSP105) is a large ATP-binding molecular chaperone that, together with HSP70 and HSP40 partners (including HSPA5/BiP and DNAJB1), prevents protein aggregation and facilitates refolding/disaggregation of misfolded substrates; it also stabilizes oncoprotein clients (c-Myc, Bcl-6) through direct physical interaction, enhances STAT3 phosphorylation via a direct interaction with STAT3, maintains ER homeostasis through interaction with HSPA5, and is transcriptionally regulated by Sp2 and translationally regulated by the m6A reader YTHDF1.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"HSPH1 (HSP110/HSP105) is a large ATP-binding molecular chaperone that protects proteins from aggregation and, in concert with the HSP70/HSP40 system, refolds and disaggregates misfolded substrates [#3]. Direct in vitro reconstitution established its core chaperone activities and revealed an elongated conformation by SAXS [#3], and it physically partners with the HSP40 co-chaperone DNAJB1 in the cytosol during cellular stress [#5] and with HSPA5/BiP to maintain endoplasmic reticulum homeostasis and restrain ER stress-driven apoptosis [#6]. Beyond generic proteostasis, HSPH1 stabilizes oncogenic clients: it physically binds c-Myc and Bcl-6 in aggressive B-cell lymphoma, with its silencing collapsing both proteins and abolishing tumorigenicity [#0], and it interacts with STAT3 to enhance STAT3 phosphorylation in inflammatory lung injury [#1]. HSPH1 expression is controlled at multiple levels — transcriptionally through direct promoter binding by Sp2 in an oxidative-stress/apoptosis axis [#4] and translationally through the m6A reader YTHDF1, which binds HSPH1 mRNA to promote its translation [#2].\",\n  \"teleology\": [\n    {\n      \"year\": 2015,\n      \"claim\": \"Established that HSPH1 acts as a client-stabilizing chaperone for specific oncoproteins rather than only as a general housekeeping chaperone, linking it to lymphoma maintenance.\",\n      \"evidence\": \"Reciprocal Co-IP plus shRNA silencing with in vitro and in vivo tumor growth assays in B-NHL cells and primary tumors\",\n      \"pmids\": [\"25573990\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct chaperone binding versus indirect stabilization of c-Myc/Bcl-6 not structurally resolved\",\n        \"ATPase dependence of the client interaction untested\",\n        \"Single lab\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Connected HSPH1 to inflammatory signal transduction by showing it binds STAT3 and promotes its phosphorylation downstream of KLF2 de-repression.\",\n      \"evidence\": \"Co-IP of HSPH1–STAT3, KLF2 and IL-1R1 perturbations, and HSPH1 inhibitor treatment in a rat acute lung injury model\",\n      \"pmids\": [\"32091104\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanism by which HSPH1 enhances STAT3 phosphorylation (direct vs. scaffolding) unresolved\",\n        \"Whether interaction requires chaperone activity not addressed\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Defined the biochemical and structural basis of human HSPH1 function by directly reconstituting its anti-aggregation, refolding and disaggregation activities and resolving its elongated conformation.\",\n      \"evidence\": \"In vitro chaperone assays with purified recombinant protein, SAXS, and biophysical characterization\",\n      \"pmids\": [\"36825649\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"High-resolution structure of substrate-bound state not determined\",\n        \"Cellular substrate repertoire not defined in this study\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified a translational control layer for HSPH1, showing the m6A reader YTHDF1 binds its mRNA to boost protein output independent of transcript level.\",\n      \"evidence\": \"RIP-qPCR for YTHDF1–HSPH1 mRNA binding plus protein/RNA level measurements and omics in gastric carcinogenesis\",\n      \"pmids\": [\"38444279\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"m6A sites on HSPH1 mRNA not mapped\",\n        \"Functional consequence of elevated HSPH1 for the tumor phenotype not isolated from broader YTHDF1 effects\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established transcriptional regulation of HSPH1 by Sp2 and placed the Sp2/HSPH1 axis in oxidative-stress-driven apoptosis and autophagy.\",\n      \"evidence\": \"Sp2–promoter binding assay with knockdown/overexpression and ROS/apoptosis/autophagy readouts in mouse spermatogonial stem cells\",\n      \"pmids\": [\"40972724\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single study and single cell model\",\n        \"Direct molecular role of HSPH1 protein downstream of Sp2 not mechanistically dissected\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Anchored HSPH1 within the canonical HSP40 co-chaperone partnership and ER chaperone machinery, supporting its role in stress proteostasis.\",\n      \"evidence\": \"Co-IP and immunofluorescence co-localization of HSPH1–DNAJB1 in hepatic IRI models, and Co-IP of HSPH1–HSPA5 with ER ultrastructure, ERS markers and rescue experiments in cardiomyocytes\",\n      \"pmids\": [\"41534252\", \"41925682\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether HSPH1–DNAJB1 and HSPH1–HSPA5 form defined stoichiometric complexes not established\",\n        \"ATPase/nucleotide-exchange cycle linking these interactions to substrate handling untested\",\n        \"Single lab per interaction\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The cellular substrate spectrum of HSPH1 and how its nucleotide-bound states couple to client stabilization, ER homeostasis and oncoprotein maintenance remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No unbiased substrate/interactome map in the corpus\",\n        \"No structure of HSPH1 bound to a defined client or co-chaperone\",\n        \"Mechanistic link between chaperone cycle and oncoprotein/STAT3 effects unestablished\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140657\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0044183\", \"supporting_discovery_ids\": [3, 5, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [3, 5, 6]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [4, 6]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"DNAJB1\", \"HSPA5\", \"STAT3\", \"MYC\", \"BCL6\", \"YTHDF1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}