CIITA is a nuclear transcriptional coactivator that drives MHC class II and associated antigen-presentation gene expression and can also enhance MHC class I transcription. It associates with promoter-bound regulatory factors, including RFX, and basal transcription machinery rather than recognizing promoter DNA directly. Nucleotide binding and regulated acetylation, phosphorylation and protein stability shape its activity. CIITA has measured protein kinase and histone acetyltransferase capacities. Context-dependent collagen repression and induction of host-defense genes broaden its transcriptional effects, while loss of functional CIITA causes MHC class II deficiency.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000122 negative regulation of transcription by RNA polymerase II | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | KEEP AS NON CORE | Summary: Retain the context-dependent transcriptional repression. Reason: The complete original abstract explicitly reports CIITA-dependent repression of type I collagen transcription and reversal by HDAC2 overexpression, with reporter and quantitative-PCR endpoints. This is compatible with a contextual repressive role distinct from the predominant MHC coactivator function. Full Results and panels were not recovered, so exact construct, promoter and cell-type assignments are not reconstructed; the positive curated IDA assertion is retained rather than rejected from that access gap. Supporting Evidence: |
| GO:0000122 negative regulation of transcription by RNA polymerase II | IMP PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | KEEP AS NON CORE | Summary: Retain the context-dependent transcriptional repression. Reason: The complete original abstract explicitly reports CIITA-dependent repression of type I collagen transcription and reversal by HDAC2 overexpression, with reporter and quantitative-PCR endpoints. This is compatible with a contextual repressive role distinct from the predominant MHC coactivator function. Full Results and panels were not recovered, so exact construct, promoter and cell-type assignments are not reconstructed; the positive curated IMP assertion is retained rather than rejected from that access gap. Supporting Evidence: |
| GO:0003677 DNA binding | TAS NOT PMID:15771576 CATERPILLER: a novel gene family important in immunity, cell... | ACCEPT | Summary: Retain the explicitly negated DNA-binding assertion. Reason: The source is a family review, and the NOT qualifier is essential: CIITA acts through promoter-bound factors rather than supplying sequence-specific DNA recognition. Actual RFX and basal-factor interaction studies independently support this coactivator mechanism. This does not negate CIITA recruitment to chromatin through protein interactions. |
| GO:0003713 transcription coactivator activity | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | ACCEPT | Summary: Retain transcriptional coactivator activity. Reason: The original abstract reports CIITA-dependent MHC II reporter activation and modulation of promoter recruitment. Independent primary RFX and TAF9 interaction experiments establish the same molecular role. The exact 2008 product and cell-to-assay mapping remain uninspected; no new mapping is invented. |
| GO:0003713 transcription coactivator activity | TAS PMID:7749984 Activation of class II MHC genes requires both the X box reg... | ACCEPT | Summary: Retain the defining MHC transcriptional coactivator function. Reason: The authentic source abstract links CIITA function to the MHC II X-box region and shows transcriptional defects in mutant products. Full primary TAF9 and RFX studies independently demonstrate protein-mediated engagement of the transcription machinery. CIITA need not bind promoter DNA directly to enable coactivation. |
| GO:0003714 transcription corepressor activity | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | KEEP AS NON CORE | Summary: Retain contextual corepressor activity. Reason: The original positive collagen-reporter and expression findings support a repressive transcriptional role in that context. HDAC2 deacetylates and antagonizes CIITA in the source abstract; it is not demonstrated to be an enzyme recruited by CIITA to execute repression. Retain the curated activity with the original full-Results and product-scope limits. Supporting Evidence: PMID:19041327 HDAC2 antagonizes CIITA activity |
| GO:0004674 protein serine/threonine kinase activity | IEA GO_REF:0000003 | ACCEPT | Summary: Retain the broad protein serine/threonine kinase class. Reason: PMID:24036077 directly assays CIITA-dependent phosphorylation, including H2B Ser36. Purification controls, in-gel denaturation/renaturation, a second human-cell preparation and a TAF1-negative immunoblot support activity attributable to CIITA. Preserve the EC-derived broad class without asserting an independently mapped threonine acceptor; the existing serine-specific annotations express the directly resolved chemistry. |
| GO:0005515 protein binding | IPI PMID:10938133 Associations and interactions between bare lymphocyte syndro... | MODIFY | Summary: Specify binding to the MHC promoter factor RFX5. Reason: The source tests human CIITA and RFX proteins by tagged co-immunoprecipitation and in-vitro translation assays. CIITA association is stronger with assembled RFX and depends on the RFX5 proline-rich region. RFX5 is a sequence-specific RNA polymerase II regulatory factor, so its binding class is informative; the experiments do not make CIITA itself a DNA-binding factor. Proposed replacements: RNA polymerase II-specific DNA-binding transcription factor binding |
| GO:0005515 protein binding | IPI PMID:16600381 ZXDC, a novel zinc finger protein that binds CIITA and activ... | KEEP AS NON CORE | Summary: Retain the experimentally supported ZXDC interaction. Reason: The source identifies a human ZXDC fragment using CIITA residues 323–1130 as yeast-two-hybrid bait and corroborates full-protein association in HEK293 cells. Its promoter occupancy and transactivation results do not establish a specific DNA-recognition motif for ZXDC or a new molecular activity of CIITA. Supported generic binding is retained as non-core under the project policy. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:17493635 The zinc finger proteins ZXDA and ZXDC form a complex that b... | KEEP AS NON CORE | Summary: Retain ZXDA association with appropriate complex scope. Reason: Tagged cellular co-immunoprecipitation supports association with CIITA. In the source’s in-vitro translation assay, CIITA binds efficiently when both ZXDA and ZXDC are present; the individual proteins did not reproduce that interaction. Preserve the ZXDA source assertion without relabeling this as purified binary affinity or assigning DNA-recognition specificity to the zinc-finger partner. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:17493635 The zinc finger proteins ZXDA and ZXDC form a complex that b... | KEEP AS NON CORE | Summary: Retain ZXDC association with appropriate complex scope. Reason: Tagged cellular co-immunoprecipitation supports association with CIITA. In the source’s in-vitro translation assay, CIITA binds efficiently when both ZXDA and ZXDC are present; the individual proteins did not reproduce that interaction. Preserve the ZXDC source assertion without relabeling this as purified binary affinity or assigning DNA-recognition specificity to the zinc-finger partner. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:21890893 SIRT1 links CIITA deacetylation to MHC II activation. | MODIFY | Summary: Specify binding to the deacetylase SIRT1. Reason: Reciprocal tagged co-immunoprecipitation in human 293 cells and endogenous association in THP-1 cells support the CIITA–SIRT1 interaction. SIRT1 is a histone deacetylase, so the class-binding term describes the partner without assigning deacetylation chemistry to CIITA. The same study treats CIITA as the regulated acetylated substrate. Proposed replacements: histone deacetylase binding |
| GO:0005515 protein binding | IPI PMID:23007646 PML promotes MHC class II gene expression by stabilizing the... | KEEP AS NON CORE | Summary: Retain the PML isoform II interaction. Reason: The study demonstrates CIITA–PML association, with the strongest stabilization and nuclear-body recruitment for PML isoform II in its tested constructs. The preserved P29590-2 partner matches that scope. Tagged association and altered nuclear residence do not establish a separate enzymatic or scaffold function for CIITA. Supporting Evidence: |
| GO:0005524 ATP binding | IEA GO_REF:0000002 | ACCEPT | Summary: Retain ATP binding with an unmapped-site caveat. Reason: ATP serves as a phosphate donor in the direct CIITA kinase assays. The tested AAE mutation does not abolish activity, so it does not establish that a unique ATP-binding pocket lies at that proposed site. Retain the original domain-derived capability without inferring identical kinetics for all products. |
| GO:0005634 nucleus | EXP PMID:11172716 Transcriptional coactivator, CIITA, is an acetyltransferase ... | ACCEPT | Summary: Retain nuclear localization. Reason: The original acetyltransferase paper remains abstract-only in available access, so its exact localization panel is not reconstructed. Independent endogenous and tagged CIITA imaging in PMID:23007646 and the current HPA observations positively establish a nuclear pool consistent with transcriptional coactivation. |
| GO:0005634 nucleus | EXP PMID:23007646 PML promotes MHC class II gene expression by stabilizing the... | ACCEPT | Summary: Retain the demonstrated nuclear pool. Reason: The source detects endogenous CIITA in IFN-gamma-treated HEp-2 nuclei and examines functional GFP-CIITA, including diffuse nucleoplasmic and PML-associated pools. This supports nuclear localization without requiring all CIITA molecules or products to occupy PML bodies. Supporting Evidence: |
| GO:0005634 nucleus | IEA GO_REF:0000044 | ACCEPT | Summary: Retain the broad nuclear compartment. Reason: The UniProt location mapping agrees with independent endogenous CIITA imaging and its promoter-associated transcriptional work. Broad nuclear location remains useful even though more precise nucleoplasmic annotations also exist. |
| GO:0005654 nucleoplasm | IDA GO_REF:0000052 | ACCEPT | Summary: Retain HPA-supported nucleoplasmic localization. Reason: The current HPA record reports supported nucleoplasmic localization. Actual selected U251MG and HEL antibody images show nuclear enrichment; the HEL dataset also includes a cytosolic pool. This supports the compartment without establishing exclusive localization or resolving the four alternative products. Supporting Evidence: GO_REF:0000052 file:human/CIITA/CIITA-source-evidence.json |
| GO:0005654 nucleoplasm | TAS Reactome:R-HSA-1031716 | ACCEPT | Summary: Retain the explicitly modeled CIITA compartment. Reason: The actual Reactome chain identifies human P33076 in entity R-HSA-1031702, annotated to nucleoplasm. CIITA is an output of the IFN-gamma-induced expression event, not a catalyst that produces itself; the source nevertheless explicitly supports this location. Supporting Evidence: Reactome:R-HSA-1031716 file:human/CIITA/CIITA-source-evidence.json |
| GO:0006355 regulation of DNA-templated transcription | IEA GO_REF:0000002 | ACCEPT | Summary: Retain the broad transcription-regulatory role. Reason: CIITA positively regulates MHC transcription and has context-dependent repression of collagen expression. The broad domain-derived regulatory term accommodates both directions; narrowing it only to positive regulation would discard a supported contextual role. |
| GO:0006955 immune response | TAS PMID:8402893 Complementation cloning of an MHC class II transactivator mu... | ACCEPT | Summary: Retain immune-response involvement through MHC expression. Reason: The authentic original complementation abstract reports restoration of MHC class II expression in human bare-lymphocyte-syndrome cells. CIITA performs transcriptional coactivation of antigen-presentation genes, providing a molecular basis for this broad immune-response annotation rather than disease necessity alone. |
| GO:0016605 PML body | IDA PMID:23007646 PML promotes MHC class II gene expression by stabilizing the... | KEEP AS NON CORE | Summary: Retain the PML-body-associated pool. Reason: The actual imaging and interaction study shows CIITA recruitment to PML bodies, especially with PML isoform II, alongside a diffuse nuclear pool. This is a supported contextual compartment that can regulate protein stability; it is not required to define every CIITA transcriptional event. Supporting Evidence: |
| GO:0016605 PML body | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Retain the PML-body-associated pool. Reason: The actual imaging and interaction study shows CIITA recruitment to PML bodies, especially with PML isoform II, alongside a diffuse nuclear pool. This is a supported contextual compartment that can regulate protein stability; it is not required to define every CIITA transcriptional event. |
| GO:0032966 negative regulation of collagen biosynthetic process | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | KEEP AS NON CORE | Summary: Retain the source-supported collagen-expression context. Reason: The complete source abstract reports CIITA repression of type I collagen transcription, measured by reporter and quantitative-PCR approaches. This supports the existing negative biosynthetic regulation at a contextual level. It does not identify CIITA as a collagen-processing enzyme, and the uninspected Results do not justify an exact product-to-cell assignment. Supporting Evidence: |
| GO:0034341 response to type II interferon | IDA PMID:32855215 MHC class II transactivator CIITA induces cell resistance to... | ACCEPT | Summary: Retain the IFN-gamma response implemented through transcription. Reason: The study separates the upstream interferon response from CIITA-dependent expression of downstream genes, including CD74. CIITA loss and reconstitution affect the antiviral transcriptional output in the tested systems. This is work by a transcriptional regulator, not direct IFN-gamma receptor activity or protease inhibition by CIITA. Supporting Evidence: |
| GO:0034341 response to type II interferon | IEA GO_REF:0000117 | ACCEPT | Summary: Retain the corroborated ARBA interferon-response assignment. Reason: The current rule has a matching CIITA FunFam pair and eukaryotic taxonomic condition set. Independent target experiments establish CIITA-dependent IFN-gamma-responsive transcription. Current rule applicability and biological support are recorded separately; historical rule execution is not reconstructed. |
| GO:0042826 histone deacetylase binding | IPI PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | KEEP AS NON CORE | Summary: Retain HDAC2 binding as a regulatory interaction. Reason: The authentic original abstract explicitly reports CIITA–HDAC2 co-immunoprecipitation and deacetylation of CIITA. This supports the partner-class binding annotation, while HDAC2 antagonizes CIITA activity in that account. It does not show CIITA deacetylase activity or prove purified binary binding; full Results and exact construct mapping remain unavailable. Supporting Evidence: |
| GO:0044877 protein-containing complex binding | IDA PMID:17493635 The zinc finger proteins ZXDA and ZXDC form a complex that b... | KEEP AS NON CORE | Summary: Retain binding to the ZXDA–ZXDC complex. Reason: The original in-vitro translation experiment shows efficient CIITA association when both ZXDA and ZXDC are present, complemented by cellular complex association. This supports the broad complex-binding assertion, but adds no distinct core molecular mechanism beyond the coactivator role and its protein interactions. Supporting Evidence: |
| GO:0045345 positive regulation of MHC class I biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: Retain curated positive regulation of MHC class I biosynthesis. Reason: The authenticated PAINT assertion is corroborated by actual human CIITA comparator experiments in PMID:20639463, including class I promoter activation and increased expression. The historical ancestral placement is not reconstructed; current rodent records are contextual evidence rather than a substitute phylogeny. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN002932643 SUPPORTS TRANSFER Human CIITA class I promoter and expression experiments in PMID:20639463 corroborate the authenticated curated propagation. Historical IBD placement, tree and MSA remain uninspected; current donor evidence does not reconstruct them. |
| GO:0045345 positive regulation of MHC class I biosynthetic process | IDA PMID:20639463 NLR family member NLRC5 is a transcriptional regulator of MH... | ACCEPT | Summary: Retain the actual CIITA comparator result. Reason: Although NLRC5 is the foreground of the paper, the full Results include CIITA-transfected human HEK293T cells, class I promoter reporters and expression measurements. CIITA moderately increases class I expression while more strongly increasing class II expression. The positive CIITA experiment is retained without transferring NLRC5 mutant or nucleotide mechanisms. Supporting Evidence: |
| GO:0045348 positive regulation of MHC class II biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: Retain curated positive regulation of MHC class II biosynthesis. Reason: CIITA performs coactivation of MHC class II promoters through regulatory and basal transcription factors. This is supported by human primary experiments and corroborates the curated PAINT node, without claiming independent reconstruction of its historical tree or IBD placement. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN002932643 SUPPORTS TRANSFER Human CIITA MHC II complementation, reporter and transcription-factor interaction experiments corroborate the authenticated curated propagation. Historical IBD placement, tree and MSA remain uninspected; current donor evidence does not reconstruct them. Supporting Evidence: GO_REF:0000033 file:human/CIITA/CIITA-source-evidence.json |
| GO:0045348 positive regulation of MHC class II biosynthetic process | IC PMID:9171108 The class II trans-activator CIITA interacts with the TBP-as... | ACCEPT | Summary: Retain MHC class II production through transcriptional activation. Reason: The source directly tests CIITA-dependent class II promoter activation and its basal-factor interaction. Positive regulation of MHC class II biosynthesis follows from that performed transcriptional step; the original IC relationship is preserved and is not relabeled as a new direct protein-synthesis assay. Supporting Evidence: |
| GO:0045348 positive regulation of MHC class II biosynthetic process | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | ACCEPT | Summary: Retain MHC class II activation reported by the source. Reason: The authentic abstract reports MHC II reporter activation by CIITA and reduction by HDAC2 overexpression or altered recruitment. This agrees with independently inspected CIITA coactivation studies. Exact 2008 construct and cell-to-assay assignments remain unavailable. |
| GO:0045892 negative regulation of DNA-templated transcription | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: Retain contextual negative transcriptional regulation. Reason: The current ARBA rule route matches the target, while the positive biological context is the reported repression of collagen transcription. Retain that direction as a non-core context rather than extending repression to all CIITA targets or declaring the electronic source incorrect because activation is its predominant role. |
| GO:0045944 positive regulation of transcription by RNA polymerase II | IBA GO_REF:0000033 | ACCEPT | Summary: Retain the curated positive Pol II transcriptional role. Reason: Actual CIITA recruitment through RFX and interaction with TAF9 supply a molecular basis for transcriptional activation. These experiments corroborate the curated PAINT transfer. Target self-inclusion and donor count are not failure criteria, and the historical ancestral node was not independently reconstructed. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN002932643 SUPPORTS TRANSFER Human CIITA basal-factor interaction and promoter activation experiments corroborate the authenticated curated propagation. Historical IBD placement, tree and MSA remain uninspected; current donor evidence does not reconstruct them. Supporting Evidence: GO_REF:0000033 file:human/CIITA/CIITA-source-evidence.json |
| GO:0045944 positive regulation of transcription by RNA polymerase II | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | ACCEPT | Summary: Retain positive Pol II regulation at MHC targets. Reason: The source abstract reports CIITA-dependent MHC II reporter activity and promoter recruitment. Independent full primary experiments establish this defining function; no precise 2008 cell or isoform mapping is inferred from the unavailable Results. |
| GO:0045944 positive regulation of transcription by RNA polymerase II | IDA PMID:20639463 NLR family member NLRC5 is a transcriptional regulator of MH... | ACCEPT | Summary: Retain direct CIITA reporter activation in the NLRC5 study. Reason: Human CIITA is an actual experimental comparator in the full Results, with promoter-reporter activation and expression measurements. The annotation does not rely merely on the paper title or transfer NLRC5-specific mechanisms to CIITA. Supporting Evidence: |
| GO:0045944 positive regulation of transcription by RNA polymerase II | IDA PMID:32855215 MHC class II transactivator CIITA induces cell resistance to... | ACCEPT | Summary: Retain transcriptional activation of host defense genes. Reason: The source compares CIITA with transcriptionally impaired variants and resolves CD74 as a relevant downstream target. CIITA supplies transcriptional regulation; the CD74 p41 product supplies the demonstrated downstream protease-related antiviral mechanism. Supporting Evidence: |
| GO:0045944 positive regulation of transcription by RNA polymerase II | IEA GO_REF:0000117 | ACCEPT | Summary: Retain the corroborated ARBA positive-transcription assignment. Reason: The current CIITA InterPro/FunFam record satisfies a current condition set of the stated rule. Independently, primary reporter and protein-interaction studies demonstrate CIITA-dependent positive transcriptional regulation. This supports the target conclusion without pretending the original rule run was reproduced. Supporting Evidence: GO_REF:0000117 file:human/CIITA/CIITA-source-evidence.json |
| GO:0045944 positive regulation of transcription by RNA polymerase II | IMP PMID:9171108 The class II trans-activator CIITA interacts with the TBP-as... | ACCEPT | Summary: Retain the CIITA activation-domain perturbation result. Reason: The source tests N-terminal CIITA activation-domain mutants in class II promoter and Gal4 reporter assays. Reduced TAF9 interaction and activation support a performed coactivator role, rather than a phenotype disconnected from transcription. The tested constructs do not establish identical activities for every current product. Supporting Evidence: PMID:9171108 interactions between TAFII32 and CIITA are responsible for activation of class II genes |
| GO:0046597 host-mediated suppression of symbiont invasion | IDA PMID:32855215 MHC class II transactivator CIITA induces cell resistance to... | KEEP AS NON CORE | Summary: Retain host antiviral protection at its transcriptional scope. Reason: CIITA expression limits Ebola glycoprotein-dependent fusion through induction of downstream genes. The study identifies CD74 p41 as a mediator; its protease-related action must not be assigned to CIITA. Retain the existing broad antiviral outcome as contextual biology rather than an additional direct invasion-blocking molecular activity. Supporting Evidence: |
| GO:0046677 response to antibiotic | IDA PMID:107465 A quantitative study of the glia of the Purkinje cell layer ... | MARK AS OVER ANNOTATED | Summary: The corrected source measures CIITA expression as an antibiotic-response readout. Reason: Official MGI J:107465 resolves to PMID:16280321, and its exact Ciita GO record points to human P33076; PMID:107465 is an unrelated glial study. In the corrected full source, geldanamycin suppresses IFN-induced CIITA transcripts and promoter activity through upstream Hsp90/CDC37-dependent signaling. GO:0046677 explicitly includes gene-expression responses, but expression of a regulated gene does not by itself establish that its protein performs the antibiotic response. Preserve the original source fields and recommend against this source-specific participation inference; no global inability to respond to antibiotics is asserted. |
| GO:0060333 type II interferon-mediated signaling pathway | IDA PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | ACCEPT | Summary: Retain the downstream transcriptional phase of IFN-gamma signaling. Reason: CIITA is an IFN-gamma-responsive coactivator of MHC II transcription, and the source abstract examines how HDAC2 changes that response and promoter recruitment. Its role lies in the transcriptional output, not cytokine binding or proximal JAK catalysis. The exact 2008 assay-to-cell mapping remains uninspected. |
| GO:0061629 RNA polymerase II-specific DNA-binding transcription factor binding | IPI PMID:19041327 HDAC2 deacetylates class II transactivator and suppresses it... | ACCEPT | Summary: Retain binding to the Pol II regulatory factor RFX5. Reason: The original abstract explicitly reports CIITA–RFX5 association and its modulation by HDAC2; the independently inspected human RFX study supports the same interaction class. RFX5 supplies sequence-specific promoter recognition, while CIITA supplies coactivation. No exact 2008 purified interface or product mapping is asserted. |
| GO:0106310 protein serine kinase activity | EXP PMID:24036077 Transcriptional coactivator CIITA, a functional homolog of T... | ACCEPT | Summary: Retain directly supported protein serine kinase activity. Reason: PMID:24036077 measures phosphorylation of H2B Ser36, TAF7 and RAP74 by human CIITA preparations. Matched extracts, in-gel renaturation, a human-cell preparation, mass-spectrometry assessment and a TAF1-negative control support CIITA-attributable activity. The original experimental annotation is retained. These assays do not establish the complete sequence of catalytic events during cellular transcription initiation. Supporting Evidence: PMID:24036077 CIITA robustly phosphorylated histone H2B at Ser36 |
| GO:0106310 protein serine kinase activity | IEA GO_REF:0000116 | ACCEPT | Summary: Retain directly supported protein serine kinase activity. Reason: PMID:24036077 measures phosphorylation of H2B Ser36, TAF7 and RAP74 by human CIITA preparations. Matched extracts, in-gel renaturation, a human-cell preparation, mass-spectrometry assessment and a TAF1-negative control support CIITA-attributable activity. The preserved RHEA reaction agrees with ATP-dependent serine phosphorylation. These assays do not establish the complete sequence of catalytic events during cellular transcription initiation. |
| GO:0140297 DNA-binding transcription factor binding | IPI PMID:9171108 The class II trans-activator CIITA interacts with the TBP-as... | MODIFY | Summary: Specify binding to a basal Pol II initiation factor. Reason: The source directly tests TAFII32, now TAF9/Q16594, and CIITA N-terminal fragments with GST pull-down and transcriptional mutants. RNA polymerase II general transcription initiation factor binding describes that basal-factor interaction more precisely than binding to a sequence-specific regulatory transcription factor. This choice does not assert that TAF9 can never contact DNA. Proposed replacements: RNA polymerase II general transcription initiation factor binding |
| GO:0004402 histone acetyltransferase activity | IDA PMID:24036077 Transcriptional coactivator CIITA, a functional homolog of T... | NEW | Summary: Add directly measured histone acetyltransferase activity. Reason: The actual later primary study measures acetyl-CoA-dependent H3/H4 acetylation by human CIITA preparations in its Methods, Results and supplementary legends, including TAF1-negative preparation controls and phosphorylation-dependent changes. This supplies direct evidence beyond the abstract-only 2001 report. The tested full-length and mutant constructs were not sequence-aligned to every current product, and the assays do not prove a complete physiological initiation mechanism. |
| GO:0005525 GTP binding | IDA PMID:10464099 GTP binding by class II transactivator: role in nuclear impo... | NEW | Summary: Add GTP binding demonstrated by the original assay. Reason: Original journal page 1402 and its complete Figure 1 legend describe GTP binding by in-vitro-translated and immunoprecipitated CIITA, with RasQ61L, NF-YA, expression correction and G1/G3/G4 motif-mutant controls. COS7 nucleotide-labeling/TLC is complementary evidence, not by itself proof of GTP-versus-GDP selectivity. Only this page and the authentic abstract were recovered; later Methods footnotes and nuclear-import Results were not inspected. This proposal assigns binding, not GTPase chemistry, a new import process or activity of all four products. Supporting Evidence: PMID:10464099 CIITA binds GTP |
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Download this section (compressed HTML)Q: Which CIITA catalytic reactions are required at endogenous MHC promoters, and can catalytic defects be separated from altered folding, nucleotide binding, recruitment or stability?
Q: How do the four human CIITA products differ in basal-factor recruitment, catalytic capacity and promoter selection under matched expression conditions?
Q: What promoter-specific mechanism accounts for CIITA-dependent collagen repression, and how does HDAC2 antagonism differ from SIRT1-mediated activation?
Q: Can the original 2008 Results and product-to-assay mapping be recovered to refine the CIITA–HDAC2 and collagen annotations?
Q: Should the antibiotic-response source be corrected from PMID:107465 to the official MGI-linked PMID:16280321 and the regulated-expression readout distinguished from participation by CIITA protein?
Experiment: Use matched, independently purified human CIITA products and separation-of-function mutants to measure nucleotide binding, serine phosphorylation and histone acetylation, with orthogonal purity controls and rescue at endogenous MHC loci.
Experiment: Compare CIITA occupancy, chromatin state and nascent transcription at MHC and collagen promoters while independently perturbing HDAC2, SIRT1 and the relevant promoter-bound factors.
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