CCT5 encodes the epsilon subunit of the cytosolic group II chaperonin TRiC/CCT. Cct5 is one of eight distinct subunits in each ring of the ATP-dependent double-ring folding chamber, contributes an equatorial ATP-binding and hydrolysis site and an apical substrate-contact surface, and participates in the sequential asymmetric ATP cycle that lets the complex fold actin, tubulin, and other cytosolic clients.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0006457 protein folding | IBA GO_REF:0000033 | ACCEPT | Summary: CCT5 participates in protein folding as an obligate subunit of TRiC/CCT, the cytosolic chaperonin that folds actin, tubulin, and other clients. Reason: Protein folding is the correct biological-process context for the chaperonin complex, supported by direct yeast CCT actin-folding assays and PANTHER/InterPro family evidence. Supporting Evidence: file:yeast/CCT5/CCT5-deep-research-falcon.md CCT5 is best defined as a **structural and catalytic component** |
| GO:0005832 chaperonin-containing T-complex | IBA GO_REF:0000033 | ACCEPT | Summary: CCT5 is a named subunit of the chaperonin-containing T-complex. Reason: Complex membership is central to the gene product function and is supported by yeast CCT complex literature and family evidence. |
| GO:0051082 unfolded protein binding | IBA GO_REF:0000033 | MODIFY | Summary: GO:0051082 is formally obsolete; Cct5 contributes to the CCT/TRiC complex's ATP-dependent protein-folding chaperone activity. Reason: GO:0051082 "unfolded protein binding" is obsolete with GO:0044183 protein folding chaperone and GO:0140309 unfolded protein holdase activity as consider terms. For Cct5, the evidence supports the GO:0140662 ATP-dependent protein folding chaperone activity of the CCT/TRiC complex; because Cct5 is one subunit of that complex, any final GOA replacement with GO:0140662 should use the contributes_to qualifier. Propagation Review Root cause: SOURCE STALE OR MISSING Failure modes: SOURCE EVIDENCE WEAK Sources checked: PANTHER:PTN004253040 · PAINT chaperonin node SOURCE STALE OR MISSING The current PTHR11353 PAINT record retains this node for conserved CCT/TRiC protein-folding biology, but it no longer carries obsolete GO:0051082 as a molecular-function IBD. Proposed replacements: ATP-dependent protein folding chaperone |
| GO:0000166 nucleotide binding | IEA GO_REF:0000043 | MODIFY | Summary: nucleotide binding is a true but overly broad family/keyword annotation for CCT5; ATP binding, ATP hydrolysis, and ATP-dependent chaperone annotations capture the specific chemistry. Reason: Nucleotide binding is too general; Cct5 carries a conserved chaperonin ATP-binding/hydrolysis domain, so GO:0005524 ATP binding and GO:0016887 ATP hydrolysis activity capture the relevant ATPase-cycle molecular functions more precisely. Proposed replacements: ATP binding ATP hydrolysis activity |
| GO:0005524 ATP binding | IEA GO_REF:0000120 | ACCEPT | Summary: CCT5 contains a conserved chaperonin ATP-binding site, but ATP binding is now represented by the current GO_REF:0000002 InterPro row. Reason: ATP binding is a valid molecular function of the conserved Cct5 equatorial chaperonin domain, and the current InterPro2GO row is the active source for this same ATPase-cycle activity. |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: CCT5 functions as part of the cytosolic TRiC/CCT chaperonin. Reason: Cytoplasm is the established location of the CCT/TRiC folding machine. |
| GO:0005832 chaperonin-containing T-complex | IEA GO_REF:0000117 | ACCEPT | Summary: CCT5 is a named subunit of the chaperonin-containing T-complex. Reason: Complex membership is central to the gene product function and is supported by yeast CCT complex literature and family evidence. |
| GO:0006457 protein folding | IEA GO_REF:0000120 | ACCEPT | Summary: CCT5 participates in protein folding as an obligate subunit of TRiC/CCT, the cytosolic chaperonin that folds actin, tubulin, and other clients. Reason: Protein folding is the correct biological-process context for the chaperonin complex, supported by direct yeast CCT actin-folding assays and PANTHER/InterPro family evidence. |
| GO:0016887 ATP hydrolysis activity | IEA GO_REF:0000002 | ACCEPT | Summary: CCT5 is a TCP-1/CCT chaperonin subunit with conserved ATPase machinery that powers TRiC/CCT conformational cycling. Reason: ATP hydrolysis is a defensible subunit-level molecular function for CCT family members and is directly tied to the chaperonin folding cycle. |
| GO:0051082 unfolded protein binding | IEA GO_REF:0000120 | MODIFY | Summary: InterPro2GO still emits obsolete GO:0051082; the CCT/TRiC complex-level replacement is ATP-dependent protein folding chaperone activity. Reason: GO:0051082 "unfolded protein binding" is obsolete with GO:0044183 protein folding chaperone and GO:0140309 unfolded protein holdase activity as consider terms. For Cct5, the evidence supports the GO:0140662 ATP-dependent protein folding chaperone activity of the CCT/TRiC complex; because Cct5 is one subunit of that complex, any final GOA replacement with GO:0140662 should use the contributes_to qualifier. Proposed replacements: ATP-dependent protein folding chaperone |
| GO:0140662 ATP-dependent protein folding chaperone | IEA GO_REF:0000002 | ACCEPT | Summary: CCT5 is an obligate subunit of the ATP-dependent TRiC/CCT folding machine. Reason: The term is appropriate as a complex-level chaperonin function; in the synthesized core function it is modeled as a contributed-to molecular function rather than a standalone activity of an isolated subunit. Supporting Evidence: PMID:16762366 The eukaryotic cytosolic chaperonin CCT is an essential ATP-dependent protein folding machine whose action is required for folding the cytoskeletal proteins actin and tubulin |
| GO:0005515 protein binding | IPI PMID:19536198 An atlas of chaperone-protein interactions in Saccharomyces ... | REMOVE | Summary: The CCT5-EFT2 interaction is not enough to make generic protein binding an informative molecular-function annotation for Cct5. Reason: The EFT2 interaction is useful physical-interaction context, but it does not define a specific replacement binding activity for this TRiC/CCT subunit; the generic protein-binding annotation should be removed in favor of Cct5's accepted chaperonin-complex and ATP-dependent folding activities. Supporting Evidence: PMID:19536198 It should be emphasized that the interactions presented are indirect TAP-tag based interactions and not direct binary interactions. |
| GO:0005515 protein binding | IPI PMID:37968396 The social and structural architecture of the yeast protein ... | REMOVE | Summary: The proteome-scale interactome helps recover CCT/TRiC connectivity but not a specific standalone protein-binding function for Cct5. Reason: This proteome-scale interactome helps recover CCT/TRiC connectivity, but it does not establish a specific protein-binding molecular function beyond Cct5's core ATP-dependent chaperonin activity. |
| GO:0006457 protein folding | IDA PMID:16762366 Quantitative actin folding reactions using yeast CCT purifie... | ACCEPT | Summary: CCT5 participates in protein folding as an obligate subunit of TRiC/CCT, the cytosolic chaperonin that folds actin, tubulin, and other clients. Reason: Protein folding is the correct biological-process context for the chaperonin complex, supported by direct yeast CCT actin-folding assays and PANTHER/InterPro family evidence. Supporting Evidence: PMID:16762366 The eukaryotic cytosolic chaperonin CCT is an essential ATP-dependent protein folding machine whose action is required for folding the cytoskeletal proteins actin and tubulin |
| GO:0005832 chaperonin-containing T-complex | IPI PMID:15704212 Physiological effects of unassembled chaperonin Cct subunits... | ACCEPT | Summary: CCT5 is a named subunit of the chaperonin-containing T-complex. Reason: Complex membership is central to the gene product function and is supported by yeast CCT complex literature and family evidence. Supporting Evidence: PMID:16762366 The eukaryotic cytosolic chaperonin CCT is an essential ATP-dependent protein folding machine whose action is required for folding the cytoskeletal proteins actin and tubulin |
| GO:0005832 chaperonin-containing T-complex | IDA PMID:16762366 Quantitative actin folding reactions using yeast CCT purifie... | ACCEPT | Summary: CCT5 is a named subunit of the chaperonin-containing T-complex. Reason: Complex membership is central to the gene product function and is supported by yeast CCT complex literature and family evidence. Supporting Evidence: PMID:15704212 Eukaryotic chaperonins, the Cct complexes, are assembled into two rings, each of which is composed of a stoichiometric array of eight different subunits |
| GO:0051082 unfolded protein binding | IDA PMID:16762366 Quantitative actin folding reactions using yeast CCT purifie... | MODIFY | Summary: The CCT3-tagged yeast complex supports CCT/TRiC foldase function, not a standalone obsolete unfolded-protein-binding activity for Cct5. Reason: GO:0051082 "unfolded protein binding" is obsolete with GO:0044183 protein folding chaperone and GO:0140309 unfolded protein holdase activity as consider terms. For Cct5, the actin-folding evidence supports the GO:0140662 ATP-dependent protein folding chaperone activity of the CCT/TRiC complex; because Cct5 is one subunit of that complex, any final GOA replacement with GO:0140662 should use the contributes_to qualifier. Proposed replacements: ATP-dependent protein folding chaperone Supporting Evidence: PMID:16762366 The eukaryotic cytosolic chaperonin CCT is an essential ATP-dependent protein folding machine whose action is required for folding the cytoskeletal proteins actin and tubulin |
| GO:0005524 ATP binding | IEA GO_REF:0000002 | ACCEPT | Summary: The current InterPro row correctly captures Cct5 ATP binding through the conserved CCT/TRiC chaperonin ATPase domain. Reason: Cct5 is a group II chaperonin subunit with an equatorial ATP-binding site; ATP binding is a direct subunit activity coupled to CCT/TRiC conformational cycling. Supporting Evidence: file:yeast/CCT5/CCT5-deep-research-falcon.md CCT5-family subunits have a canonical chaperonin architecture with **equatorial** (ATP binding and ring contacts) |
| GO:0005832 chaperonin-containing T-complex | IPI PMID:21701561 The crystal structure of yeast CCT reveals intrinsic asymmet... | ACCEPT | Summary: The yeast CCT-actin crystal structure supports CCT5 as a subunit of the chaperonin-containing T-complex. Reason: The yeast CCT-actin crystal structure resolved the hetero-octameric CCT subunit organization and directly supports CCT5 complex membership. Supporting Evidence: PMID:21701561 We have solved the crystal structure of yeast CCT in complex with actin |
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Download this section (compressed HTML)Q: How does the high-ATP-affinity Cct5 subunit shape client progression through the yeast TRiC/CCT ATPase cycle?
Experiment: Compare ATPase-cycle reporters, client folding assays, and viability for targeted CCT5 ATP-pocket alleles in yeast, separating assembled-complex abundance from kinetic effects.
Hypothesis: Cct5 ATP binding/hydrolysis helps set the timing of TRiC/CCT chamber closure for actin and tubulin clients.
Type: site-directed mutagenesis with chaperonin folding and ATPase assays
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Download this section (compressed HTML)Subunit of the cytosolic chaperonin Cct ring complex; related to Tcp1p, required for the assembly of actin and tubulins in vivo
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