Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0006457 protein folding	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic inference is well supported. HSP60 is a group I chaperonin whose primary function is protein folding in the mitochondrial matrix. PMID:2645524 showed HSP60 is essential for assembly of imported proteins, and PMID:1978929 demonstrated it is required for its own de novo folding. Supporting Evidence: PMID:2645524 Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria. PMID:1978929 Hsp60 monomers form a complex arranged as two stacked 7-mer rings. This 14-mer complex binds unfolded proteins at its surface, then seems to catalyse their folding in an ATP-dependent process. file:yeast/HSP60/HSP60-deep-research-falcon.md In yeast specifically, Hsp60 forms a 14-subunit double-ring (two heptameric rings), creating a cavity that can accommodate client proteins up to ~50 kDa, and imported precursor proteins transiently associate with Hsp60 as incompletely folded intermediates before ATP-dependent folding/release.
GO:0007005 mitochondrion organization	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic inference is supported by experimental evidence. HSP60 is essential for mitochondrial biogenesis; loss-of-function mutants show defects in mitochondrial protein assembly and mtDNA maintenance (PMID:2645524, PMID:14597775). Supporting Evidence: PMID:2645524 Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria. PMID:14597775 A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae. file:yeast/HSP60/HSP60-deep-research-falcon.md HSP60 is essential for viability: deletion/null mutants are inviable due to severe mitochondrial folding defects.
GO:0005743 mitochondrial inner membrane	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: HSP60 is primarily a soluble matrix protein. There is some association with the inner membrane, possibly through its role in the TIM23-PAM import machinery, but the primary active location is the mitochondrial matrix. This IBA annotation is acceptable as HSP60 may be active at the inner membrane during protein import. Reason: HSP60 is primarily a matrix protein; inner membrane association is secondary to its import-related functions.
GO:0005759 mitochondrial matrix	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic inference consistent with UniProt annotation (PMID:11502169) and experimental localization data. The mitochondrial matrix is the primary location where HSP60 functions. Supporting Evidence: PMID:11502169 Yeast mitochondrial dehydrogenases are associated in a supramolecular complex. file:yeast/HSP60/HSP60-deep-research-falcon.md Yeast Hsp60 is produced as a mitochondrial precursor with an N-terminal matrix-targeting presequence, cleaved by MPP after residue 21, consistent with mitochondrial import and processing to a mature matrix protein.
GO:0034514 mitochondrial unfolded protein response	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: Phylogenetic inference. HSP60 expression is induced by mitochondrial stress and heat shock. As a major mitochondrial chaperonin, it is a key effector of the mitochondrial unfolded protein response. This is a secondary/responsive function rather than core enzymatic activity. Reason: This is a stress response pathway annotation; the core function is ATP-dependent protein folding.
GO:0045041 protein import into mitochondrial intermembrane space	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: Phylogenetic inference supported by experimental evidence from PMID:1347713, which demonstrated that HSP60 couples protein import into the matrix with export to the intermembrane space. Reason: This is a secondary function of HSP60 related to its role in the TIM23/PAM import pathway; the core function is protein folding in the matrix. Supporting Evidence: PMID:1347713 Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space.
GO:0051087 protein-folding chaperone binding	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic inference supported by direct experimental evidence. PMID:9256426 demonstrated physical interaction between HSP60 and HSP10 (co-chaperonin) with measured binding constants (Kd 0.9 nM in ADP). Supporting Evidence: PMID:9256426 In the presence of ADP, one molecule of hsp10 binds to hsp60 with an apparent Kd of 0.9 nM and a second molecule of hsp10 binds with a Kd of 24 nM. file:yeast/HSP60/HSP60-deep-research-falcon.md the co-chaperonin Hsp10 (GroES-like) caps the cavity (“lid”), enabling an encapsulated folding environment; ATP hydrolysis and nucleotide exchange govern release/reset.
GO:0000166 nucleotide binding	IEA GO_REF:0000043	MODIFY	Summary: Overly general IEA annotation based on UniProt keyword. HSP60 specifically binds ATP; the more specific term GO:0005524 (ATP binding) is already annotated. Reason: Too general; ATP binding is the correct specific term. Proposed replacements: ATP binding
GO:0005524 ATP binding	IEA GO_REF:0000120	ACCEPT	Summary: IEA annotation consistent with HSP60 being an ATPase chaperonin. HSP60 binds and hydrolyzes ATP as part of its folding cycle. Supported by direct assay in PMID:7902576 and PMID:9256426. Supporting Evidence: PMID:7902576 Identification and functional analysis of chaperonin 10, the groES homolog from yeast mitochondria. PMID:9256426 Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
GO:0005737 cytoplasm	IEA GO_REF:0000117	REMOVE	Summary: ARBA machine learning annotation. HSP60 is synthesized in the cytoplasm as a precursor but its functional location is the mitochondrial matrix. This annotation is misleading as it does not reflect the active location of the protein. Falcon notes that a small extra-mitochondrial pool (~15-20% cytoplasmic) has been reported for HSP60 in higher eukaryotes, but explicitly flags this distribution as "not yeast-specific", so it does not justify a yeast cytoplasm annotation. Reason: HSP60 is a mitochondrial matrix protein. Cytoplasmic presence is only transient during import; the reported cytoplasmic pool is from mammalian studies, not yeast. Supporting Evidence: file:yeast/HSP60/HSP60-deep-research-falcon.md In broader eukaryotic contexts, HSP60 is predominantly mitochondrial and can also be detected in extra-mitochondrial compartments; one 2024 review summarizes a distribution of ~80–85% mitochondrial and ~15–20% cytoplasmic for HSP60 (not yeast-specific).
GO:0005759 mitochondrial matrix	IEA GO_REF:0000044	ACCEPT	Summary: IEA annotation based on UniProt subcellular location. Consistent with IBA and experimental evidence. Redundant with IBA annotation but correct.
GO:0006457 protein folding	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based IEA annotation. Redundant with IBA and IMP evidence for the same term, but correct.
GO:0042026 protein refolding	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based IEA annotation. Consistent with experimental evidence from PMID:1359644 and PMID:9256426 showing HSP60 mediates ATP-dependent refolding of denatured proteins. Supporting Evidence: PMID:1359644 Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures. PMID:9256426 In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
GO:0051082 unfolded protein binding	IEA GO_REF:0000117	MODIFY	Summary: GO:0051082 is proposed for obsoletion. HSP60 is an ATP-dependent group I chaperonin (foldase) that actively folds proteins, not merely a passive binding protein. The correct term is GO:0140662 (ATP-dependent protein folding chaperone). Reason: GO:0051082 is proposed for obsoletion. HSP60 is a bona fide ATP-dependent foldase chaperonin, not a passive unfolded protein binder. Proposed replacements: ATP-dependent protein folding chaperone
GO:0140662 ATP-dependent protein folding chaperone	IEA GO_REF:0000002	ACCEPT	Summary: This is the correct and most informative molecular function term for HSP60. It is a group I chaperonin that uses ATP hydrolysis to fold substrate proteins within its central cavity. Supported by PMID:7902576 (ATPase activity), PMID:9256426 (ATP-dependent refolding of malate dehydrogenase), and PMID:1359644 (ATP-dependent refolding of DHFR). Reason: This is the primary molecular function of HSP60 and the correct replacement for GO:0051082. Supporting Evidence: PMID:9256426 In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase. PMID:1359644 Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures. file:yeast/HSP60/HSP60-deep-research-falcon.md ATP-dependent protein folding chaperonin for mitochondrial matrix proteins, particularly those imported into mitochondria as unfolded precursors. file:yeast/HSP60/HSP60-deep-research-falcon.md Hsp60 does not catalyze a chemical transformation of a small molecule substrate; rather, it catalyzes conformational maturation of polypeptides by providing a protected folding environment and coordinating binding/release with ATP hydrolysis and Hsp10 capping.
GO:0005515 protein binding	IPI PMID:11805837 Systematic identification of protein complexes in Saccharomy...	MARK AS OVER ANNOTATED	Summary: High-throughput mass spectrometry identification of protein complexes. Protein binding is uninformative for a chaperonin that interacts with many client proteins. The binding reflects chaperone-client interactions. Reason: Protein binding is uninformative for a chaperonin; its binding to clients is part of its ATP-dependent protein folding chaperone activity.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	MARK AS OVER ANNOTATED	Summary: Same rationale as above. Protein binding is uninformative for a chaperonin. Reason: Protein binding is uninformative for a chaperonin.
GO:0005515 protein binding	IPI PMID:16554755 Global landscape of protein complexes in the yeast Saccharom...	MARK AS OVER ANNOTATED	Summary: Same rationale as above. Protein binding is uninformative for a chaperonin. Reason: Protein binding is uninformative for a chaperonin.
GO:0005515 protein binding	IPI PMID:19536198 An atlas of chaperone-protein interactions in Saccharomyces ...	MARK AS OVER ANNOTATED	Summary: Chaperone-protein interaction atlas. Protein binding is uninformative for a chaperonin. Reason: Protein binding is uninformative for a chaperonin.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	MARK AS OVER ANNOTATED	Summary: Same rationale as above. Reason: Protein binding is uninformative for a chaperonin.
GO:0042645 mitochondrial nucleoid	IDA PMID:14597775 A function for the mitochondrial chaperonin Hsp60 in the str...	ACCEPT	Summary: Direct experimental evidence showing HSP60 localizes to mitochondrial nucleoids. PMID:14597775 demonstrated a function for HSP60 in the structure and transmission of mtDNA nucleoids. Supporting Evidence: PMID:14597775 A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae.
GO:0051082 unfolded protein binding	IMP PMID:1359644 Prevention of protein denaturation under heat stress by the ...	MODIFY	Summary: PMID:1359644 showed that HSP60 forms complexes with polypeptides in organelles exposed to heat stress and mediates ATP-dependent refolding. This is active chaperonin-mediated folding, not passive unfolded protein binding. The correct term is GO:0140662 (ATP-dependent protein folding chaperone). Reason: GO:0051082 is proposed for obsoletion. The experiment demonstrates ATP-dependent chaperonin folding activity, which is GO:0140662. Proposed replacements: ATP-dependent protein folding chaperone Supporting Evidence: PMID:1359644 Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
GO:0005739 mitochondrion	HDA PMID:24769239 Quantitative variations of the mitochondrial proteome and ph...	KEEP AS NON CORE	Summary: High-throughput proteomics of mitochondria. Consistent with known localization. Less specific than mitochondrial matrix but correct. Reason: Correct but less specific than mitochondrial matrix.
GO:0005739 mitochondrion	HDA PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria.	KEEP AS NON CORE	Summary: Mitochondrial proteomics. Consistent with known localization. Reason: Correct but less specific than mitochondrial matrix.
GO:0005739 mitochondrion	HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen...	KEEP AS NON CORE	Summary: Mitochondrial proteomics. Consistent with known localization. Reason: Correct but less specific than mitochondrial matrix.
GO:0003688 DNA replication origin binding	IDA PMID:10869431 In organello formaldehyde crosslinking of proteins to mtDNA:...	KEEP AS NON CORE	Summary: PMID:10869431 used in organello formaldehyde crosslinking to identify HSP60 as a bifunctional protein that binds mtDNA replication origins. This is a secondary moonlighting function related to mtDNA maintenance, not the core protein folding function. Reason: This is a moonlighting function related to mtDNA nucleoid maintenance, distinct from the core chaperonin folding activity. Supporting Evidence: PMID:10869431 In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins.
GO:0003697 single-stranded DNA binding	IDA PMID:10869431 In organello formaldehyde crosslinking of proteins to mtDNA:...	KEEP AS NON CORE	Summary: Same paper as DNA replication origin binding. HSP60 was shown to bind ssDNA in the context of mtDNA nucleoid maintenance. This is a moonlighting function. Reason: Moonlighting function related to mtDNA maintenance; not the core chaperonin activity.
GO:0005739 mitochondrion	IDA PMID:11502169 Yeast mitochondrial dehydrogenases are associated in a supra...	KEEP AS NON CORE	Summary: Direct experimental evidence of mitochondrial localization from protein sequencing study. Reason: Correct but less specific than mitochondrial matrix.
GO:0005739 mitochondrion	IDA PMID:8097278 Loss of mitochondrial hsp60 function: nonequivalent effects ...	KEEP AS NON CORE	Summary: Direct experimental evidence of mitochondrial localization. PMID:8097278 studied loss of mitochondrial hsp60 function. Reason: Correct but less specific than mitochondrial matrix.
GO:0006458 'de novo' protein folding	IMP PMID:1978929 The mitochondrial chaperonin hsp60 is required for its own a...	ACCEPT	Summary: PMID:1978929 demonstrated that HSP60 is required for its own assembly - newly imported HSP60 monomers require functional pre-existing HSP60 complex to fold and assemble into the tetradecamer. This is direct evidence for de novo protein folding activity. Supporting Evidence: PMID:1978929 Functional pre-existing hsp60 complex is required in order to form new, assembled, 14-mer. Subunits imported in vitro are assembled with a surprisingly fast half-time of 5-10 min, indicative of a catalysed reaction.
GO:0016887 ATP hydrolysis activity	IDA PMID:7902576 Identification and functional analysis of chaperonin 10, the...	ACCEPT	Summary: PMID:7902576 directly measured ATPase activity of yeast HSP60 (cpn60). The ATPase activity is intrinsic to the chaperonin folding cycle. Supporting Evidence: PMID:7902576 Identification and functional analysis of chaperonin 10, the groES homolog from yeast mitochondria. PMID:9256426 Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
GO:0016887 ATP hydrolysis activity	IDA PMID:9256426 Significance of chaperonin 10-mediated inhibition of ATP hyd...	ACCEPT	Summary: PMID:9256426 demonstrated that HSP60 has ATPase activity that is inhibited approximately 40% by HSP10. This inhibition is mechanistically coupled to the folding cycle. Supporting Evidence: PMID:9256426 Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
GO:0042026 protein refolding	IMP PMID:1359644 Prevention of protein denaturation under heat stress by the ...	ACCEPT	Summary: PMID:1359644 showed HSP60 mediates ATP-dependent refolding of heat-denatured DHFR in vitro, preventing aggregation and restoring activity. Supporting Evidence: PMID:1359644 Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
GO:0042026 protein refolding	IDA PMID:9256426 Significance of chaperonin 10-mediated inhibition of ATP hyd...	ACCEPT	Summary: PMID:9256426 demonstrated in vitro refolding of mitochondrial malate dehydrogenase by purified HSP60/HSP10 in the presence of ATP. Supporting Evidence: PMID:9256426 In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
GO:0042645 mitochondrial nucleoid	IDA PMID:10869431 In organello formaldehyde crosslinking of proteins to mtDNA:...	KEEP AS NON CORE	Summary: Crosslinking study showing HSP60 associates with mtDNA. Consistent with role in nucleoid structure. Reason: Moonlighting function related to mtDNA maintenance.
GO:0045041 protein import into mitochondrial intermembrane space	IMP PMID:1347713 Antifolding activity of hsp60 couples protein import into th...	KEEP AS NON CORE	Summary: PMID:1347713 demonstrated that HSP60 antifolding activity couples protein import into the matrix with export to the intermembrane space. This is a downstream consequence of its chaperonin activity rather than a distinct function. Reason: Secondary to core chaperonin folding activity. Supporting Evidence: PMID:1347713 Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space. file:yeast/HSP60/HSP60-deep-research-falcon.md Yeast mitochondrial precursor proteins associate with Hsp60 as folding intermediates after import; ATP-dependent folding/release has been demonstrated in classical imported substrate experiments (e.g., Su9-DHFR) cited in major yeast chaperone reviews.
GO:0050821 protein stabilization	IMP PMID:1359644 Prevention of protein denaturation under heat stress by the ...	KEEP AS NON CORE	Summary: PMID:1359644 showed HSP60 prevents thermal inactivation of DHFR in vivo and prevents aggregation in vitro. Protein stabilization is a consequence of its chaperonin activity during heat stress. Reason: Consequence of chaperonin activity under stress, not a distinct core function. Supporting Evidence: PMID:1359644 The Hsp60 was required to prevent the thermal inactivation in vivo of native dihydrofolate reductase (DHFR) imported into mitochondria.
GO:0051087 protein-folding chaperone binding	IPI PMID:9256426 Significance of chaperonin 10-mediated inhibition of ATP hyd...	ACCEPT	Summary: PMID:9256426 directly measured HSP60-HSP10 binding with high affinity (Kd 0.9 nM). This interaction is central to the chaperonin folding mechanism. Supporting Evidence: PMID:9256426 In the presence of ADP, one molecule of hsp10 binds to hsp60 with an apparent Kd of 0.9 nM and a second molecule of hsp10 binds with a Kd of 24 nM.
GO:0051131 chaperone-mediated protein complex assembly	IMP PMID:2645524 Mitochondrial heat-shock protein hsp60 is essential for asse...	ACCEPT	Summary: PMID:2645524 demonstrated that HSP60 is essential for assembly of imported proteins into oligomeric complexes. This is a key aspect of its chaperonin function. Supporting Evidence: PMID:2645524 A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix.
GO:0051604 protein maturation	IMP PMID:8097278 Loss of mitochondrial hsp60 function: nonequivalent effects ...	KEEP AS NON CORE	Summary: PMID:8097278 studied loss of HSP60 function effects on matrix-targeted and intermembrane-targeted proteins, showing HSP60 is needed for proper maturation. This is a downstream consequence of its folding activity. Reason: Protein maturation is a downstream consequence of chaperonin-assisted folding.
GO:0005743 mitochondrial inner membrane	TAS Reactome:R-SCE-1252253	KEEP AS NON CORE	Summary: Reactome annotation based on TIM23 PAM complex translocation pathway. HSP60 participates in this process but is primarily a matrix protein. Reason: Association with inner membrane during protein import; primary location is matrix.
GO:0005743 mitochondrial inner membrane	TAS Reactome:R-SCE-1268014	KEEP AS NON CORE	Summary: Reactome annotation for precursor protein entry into TIM23 PAM complex. Same rationale as above. Reason: Association with inner membrane during protein import.
GO:0005743 mitochondrial inner membrane	TAS Reactome:R-SCE-1268017	KEEP AS NON CORE	Summary: Reactome annotation for MPP presequence hydrolysis. Same rationale. Reason: Association with inner membrane during protein import.
GO:0005758 mitochondrial intermembrane space	TAS Reactome:R-SCE-1252255	REMOVE	Summary: Reactome annotation suggesting HSP60 is in the intermembrane space during the TOM40/TOM70 translocation process. HSP60 is not a resident IMS protein; it participates in protein import that transits the IMS. Reason: HSP60 is not a resident IMS protein. This annotation reflects its transient role in the import pathway.
GO:0005758 mitochondrial intermembrane space	TAS Reactome:R-SCE-1268014	REMOVE	Summary: Same rationale as above. HSP60 is a matrix protein, not an IMS resident. Reason: HSP60 is not a resident IMS protein.
GO:0005759 mitochondrial matrix	TAS Reactome:R-SCE-1252253	ACCEPT	Summary: Reactome annotation consistent with known matrix localization.
GO:0005829 cytosol	TAS Reactome:R-SCE-1252255	REMOVE	Summary: Reactome annotation. HSP60 is synthesized in the cytosol but is rapidly imported into mitochondria. The cytosol is not where HSP60 functions. Reason: HSP60 functions in the mitochondrial matrix, not the cytosol. Cytosolic presence is only transient during import.

Core Functions

Mitochondrial group I chaperonin (GroEL homolog) that forms a tetradecameric double-ring complex. Uses ATP hydrolysis to drive the folding of newly imported and heat-denatured proteins within its central cavity. Cooperates with the co-chaperonin HSP10 (GroES homolog), which caps the folding chamber and modulates ATPase activity. Essential for mitochondrial biogenesis and protein homeostasis.

Molecular Function:

ATP-dependent protein folding chaperone

Directly Involved In:

protein folding protein refolding chaperone-mediated protein complex assembly

Cellular Locations:

mitochondrial matrix

Supporting Evidence:

PMID:9256426
In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
PMID:2645524
A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix.
PMID:1359644
Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000043

Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

GO_REF:0000120

Combined Automated Annotation using Multiple IEA Methods

PMID:10869431

In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins.

HSP60 crosslinks to mtDNA and binds replication origins and ssDNA

"In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins."

PMID:11502169

Yeast mitochondrial dehydrogenases are associated in a supramolecular complex.

HSP60 identified in mitochondria by protein sequencing

"Yeast mitochondrial dehydrogenases are associated in a supramolecular complex."

PMID:11805837

Systematic identification of protein complexes in Saccharomyces cerevisiae by mass spectrometry.

PMID:1347713

Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space.

HSP60 couples import to IMS with its antifolding activity

"Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space."

PMID:1359644

Prevention of protein denaturation under heat stress by the chaperonin Hsp60.

HSP60 forms complexes with polypeptides under heat stress and mediates ATP-dependent refolding

"Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures."
HSP60 prevents thermal inactivation of imported DHFR in vivo

"The Hsp60 was required to prevent the thermal inactivation in vivo of native dihydrofolate reductase (DHFR) imported into mitochondria."

PMID:14576278

The proteome of Saccharomyces cerevisiae mitochondria.

PMID:14597775

A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae.

HSP60 functions in mtDNA nucleoid structure and transmission

"A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae."

PMID:16429126

Proteome survey reveals modularity of the yeast cell machinery.

PMID:16554755

Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.

PMID:16823961

Toward the complete yeast mitochondrial proteome: multidimensional separation techniques for mitochondrial proteomics.

PMID:19536198

An atlas of chaperone-protein interactions in Saccharomyces cerevisiae: implications to protein folding pathways in the cell.

PMID:1978929

The mitochondrial chaperonin hsp60 is required for its own assembly.

HSP60 requires pre-existing functional complex for self-assembly

"Functional pre-existing hsp60 complex is required in order to form new, assembled, 14-mer."

PMID:24769239

Quantitative variations of the mitochondrial proteome and phosphoproteome during fermentative and respiratory growth in Saccharomyces cerevisiae.

PMID:2645524

Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria.

HSP60 is essential for assembly of imported mitochondrial proteins

"A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix."

PMID:37968396

The social and structural architecture of the yeast protein interactome.

PMID:7902576

Identification and functional analysis of chaperonin 10, the groES homolog from yeast mitochondria.

Yeast cpn60 has ATPase activity; cpn10 required for cpn60-mediated refolding of Rubisco

"When dimeric ribulose-1,5-bisphosphate carboxylase (Rubisco) is denatured and allowed to bind to yeast cpn60, subsequent refolding of Rubisco is strictly dependent upon yeast cpn10."

PMID:8097278

Loss of mitochondrial hsp60 function: nonequivalent effects on matrix-targeted and intermembrane-targeted proteins.

Loss of HSP60 function has different effects on matrix vs IMS proteins

"Loss of mitochondrial hsp60 function: nonequivalent effects on matrix-targeted and intermembrane-targeted proteins."

PMID:9256426

Significance of chaperonin 10-mediated inhibition of ATP hydrolysis by chaperonin 60.

HSP10 binds HSP60 with Kd 0.9 nM in ADP

"In the presence of ADP, one molecule of hsp10 binds to hsp60 with an apparent Kd of 0.9 nM and a second molecule of hsp10 binds with a Kd of 24 nM."
HSP60/HSP10 mediates ATP-dependent refolding of malate dehydrogenase

"In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase."
HSP10 inhibits HSP60 ATPase by 40%, which is coupled to folding

"Hsp10 inhibits the ATPase activity of hsp60 by about 40%."

Reactome:R-SCE-1252253

TIM23 PAM complex translocates proteins from the mitochondrial intermembrane space to the mitochondrial matrix

Reactome:R-SCE-1252255

TOM40:TOM70 complex translocates proteins from the cytosol to the mitochondrial intermembrane space

Reactome:R-SCE-1268014

Precursor proteins enter TIM23 PAM complex

Reactome:R-SCE-1268017

MPP hydrolyzes presequence of matrix precursors

file:yeast/HSP60/HSP60-deep-research-falcon.md

Falcon deep research report on yeast HSP60 (P19882 / YLR259C)

The primary molecular function of yeast Hsp60 is as an ATP-dependent protein folding chaperonin for mitochondrial matrix proteins, especially those imported as unfolded precursors; it does not perform a small-molecule chemical reaction but catalyzes conformational maturation of polypeptides.

"ATP-dependent **protein folding chaperonin** for mitochondrial matrix proteins, particularly those imported into mitochondria as unfolded precursors. (verghese2012biologyofthe pages 29-30, cabiscol2002mitochondrialhsp60resistance pages 1-1)"
Hsp60 catalyzes conformational maturation of polypeptides by providing a protected folding environment and coordinating substrate binding/release with ATP hydrolysis and Hsp10 capping, rather than transforming a small-molecule substrate.

"Hsp60 does not catalyze a chemical transformation of a small molecule substrate; rather, it catalyzes **conformational maturation of polypeptides** by providing a protected folding environment and coordinating binding/release with ATP hydrolysis and Hsp10 capping."
In yeast Hsp60 forms a 14-subunit double ring (two heptameric rings) enclosing a cavity that accommodates clients up to ~50 kDa; imported precursors transiently associate as incompletely folded intermediates before ATP-dependent folding/release.

"In yeast specifically, Hsp60 forms a **14-subunit double-ring (two heptameric rings)**, creating a cavity that can accommodate client proteins up to ~**50 kDa**, and imported precursor proteins transiently associate with Hsp60 as incompletely folded intermediates before ATP-dependent folding/release."
The co-chaperonin Hsp10 (GroES-like) caps the folding cavity as a lid to create an encapsulated folding environment, and ATP hydrolysis plus nucleotide exchange govern substrate release and cycle reset.

"the co-chaperonin **Hsp10 (GroES-like)** caps the cavity (“lid”), enabling an encapsulated folding environment; ATP hydrolysis and nucleotide exchange govern release/reset."
Yeast Hsp60 is synthesized as a mitochondrial precursor with an N-terminal matrix-targeting presequence that is cleaved by the mitochondrial processing peptidase (MPP) after residue 21, yielding the mature matrix protein.

"Yeast Hsp60 is produced as a **mitochondrial precursor** with an N-terminal matrix-targeting presequence, cleaved by MPP after residue 21, consistent with mitochondrial import and processing to a mature matrix protein."
HSP60 is essential for viability; deletion/null mutants are inviable due to severe mitochondrial folding defects.

"HSP60 is **essential for viability**: deletion/null mutants are inviable due to severe mitochondrial folding defects."
Representative Hsp60-dependent yeast clients include F1-ATPase subunits, cytochrome b2, and the Rieske Fe-S protein; conditional Hsp60 mutants accumulate insoluble matrix aggregates.

"Representative mitochondrial proteins discussed as Hsp60-dependent/affected in yeast reviews include **F1-ATPase subunits**, **cytochrome b2**, and the **Rieske Fe–S protein**; conditional mutants can accumulate **insoluble matrix aggregates**."
The temperature-sensitive mif4 allele (Gly298Asp) causes the ~840 kDa Hsp60 complex to become insoluble within ~2 hours after temperature shift.

"A temperature-sensitive **mif4** allele (Gly298→Asp) has been reported to cause the existing ~**840 kDa** Hsp60 complex to become insoluble within ~2 hours after temperature shift, pelleting at 15,000×g; this phenotype is described in a chaperonin chronologue review synthesizing genetic/biochemical evidence."
Hsp60 is induced 2-3 fold at 42 degrees C and protects Fe/S enzymes from oxidative inactivation in a dose-dependent manner; reduced Hsp60 increases the labile iron pool, and iron chelation partially rescues survival and oxidation phenotypes, linking Hsp60 to oxidative-stress defense.

"The same work reports Hsp60 is induced **2–3× at 42°C** and that protection of Fe/S enzymes from oxidative inactivation is **dose-dependent** on Hsp60 levels; reduced Hsp60 increased the labile iron pool (calcein assay), and iron chelation (deferoxamine) partially rescued survival and oxidation phenotypes."
A reported extra-mitochondrial pool of HSP60 (~15-20% cytoplasmic, ~80-85% mitochondrial) is explicitly noted as not yeast-specific, so it does not support a cytoplasmic localization annotation for yeast Hsp60.

"In broader eukaryotic contexts, HSP60 is predominantly mitochondrial and can also be detected in extra-mitochondrial compartments; one 2024 review summarizes a distribution of ~**80–85% mitochondrial** and ~**15–20% cytoplasmic** for HSP60 (not yeast-specific)."

Deep Research

Falcon

(HSP60-deep-research-falcon.md)

this with annotations you find in gene/protein databases, but these can be outdated or inaccurate. Falcon Edison Scientific Literature 24 citations 2 artifacts 2026-05-30T10:09:34.220690

Edison artifact artifact-00 (text/markdown)

## Context ID: pqac-00000015 I have extracted Table 3, which lists the mitochondrial chaperones, including the Hsp60 and Hsp10 chaperonins. I have also included (image/png)

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.

Research Report: Saccharomyces cerevisiae HSP60 (UniProt P19882; ORF YLR259C)

0) Target verification (mandatory)

The research target is the budding yeast mitochondrial chaperonin Hsp60 encoded by HSP60 with systematic locus YLR259C, which is a nuclear-encoded mitochondrial precursor protein imported into the mitochondrial matrix and processed by the mitochondrial processing peptidase (MPP). A high-authority chaperonin review explicitly describes yeast Hsp60 as a 572-aa ORF, with a classical mitochondrial targeting presequence cleaved after residue 21, and identifies it as a GroEL/Cpn60-family chaperonin required for folding of imported mitochondrial proteins. (horwich2020chaperoninassistedproteinfolding pages 21-21)

1) Key concepts and definitions (current understanding)

1.1 What Hsp60 is

Hsp60 (also called Cpn60) is a Type I / Group I chaperonin (GroEL-like) that forms an oligomeric folding cage to assist protein folding. In yeast, Hsp60 is the mitochondrial matrix chaperonin. (verghese2012biologyofthe pages 29-30)

1.2 Core mechanism: ATP-driven folding in an encapsulated cavity

Authoritative reviews describe the canonical Group I chaperonin cycle as follows: (i) non-native polypeptides are captured in the chaperonin cavity, (ii) ATP binding drives conformational changes, and (iii) the co-chaperonin Hsp10 (GroES-like) caps the cavity (“lid”), enabling an encapsulated folding environment; ATP hydrolysis and nucleotide exchange govern release/reset. (singh2024molecularchaperoninhsp60 pages 2-4, singh2024molecularchaperoninhsp60 pages 1-2)

In yeast specifically, Hsp60 forms a 14-subunit double-ring (two heptameric rings), creating a cavity that can accommodate client proteins up to ~50 kDa, and imported precursor proteins transiently associate with Hsp60 as incompletely folded intermediates before ATP-dependent folding/release. (verghese2012biologyofthe pages 29-30)

1.3 Cellular role in mitochondrial protein biogenesis and proteostasis

Because most mitochondrial proteins are nuclear encoded and imported post-translationally, mitochondria require dedicated chaperone systems. Yeast Hsp60 is positioned as a central component of this mitochondrial proteostasis network, partnering with Hsp10 and other mitochondrial chaperones in folding and translocation-linked quality control. (verghese2012biologyofthe pages 26-27, verghese2012biologyofthe pages 29-30)

2) Functional annotation for yeast HSP60 (what it does)

2.1 Primary molecular function

Molecular function: ATP-dependent protein folding chaperonin for mitochondrial matrix proteins, particularly those imported into mitochondria as unfolded precursors. (verghese2012biologyofthe pages 29-30, cabiscol2002mitochondrialhsp60resistance pages 1-1)

Reaction/substrate specificity (non-enzymatic): Hsp60 does not catalyze a chemical transformation of a small molecule substrate; rather, it catalyzes conformational maturation of polypeptides by providing a protected folding environment and coordinating binding/release with ATP hydrolysis and Hsp10 capping. (verghese2012biologyofthe pages 29-30, singh2024molecularchaperoninhsp60 pages 2-4)

2.2 Subcellular localization and targeting

Yeast Hsp60 is produced as a mitochondrial precursor with an N-terminal matrix-targeting presequence, cleaved by MPP after residue 21, consistent with mitochondrial import and processing to a mature matrix protein. (horwich2020chaperoninassistedproteinfolding pages 21-21)

In broader eukaryotic contexts, HSP60 is predominantly mitochondrial and can also be detected in extra-mitochondrial compartments; one 2024 review summarizes a distribution of ~80–85% mitochondrial and ~15–20% cytoplasmic for HSP60 (not yeast-specific). (singh2024molecularchaperoninhsp60 pages 2-4)

3) Biological processes, pathways, and key client proteins

3.1 Mitochondrial protein import and folding pathway

Yeast mitochondrial precursor proteins associate with Hsp60 as folding intermediates after import; ATP-dependent folding/release has been demonstrated in classical imported substrate experiments (e.g., Su9-DHFR) cited in major yeast chaperone reviews. (verghese2012biologyofthe pages 29-30)

3.2 Essentiality and representative clients

HSP60 is essential for viability: deletion/null mutants are inviable due to severe mitochondrial folding defects. (verghese2012biologyofthe pages 29-30, horwich2020chaperoninassistedproteinfolding pages 21-21)

Representative mitochondrial proteins discussed as Hsp60-dependent/affected in yeast reviews include F1-ATPase subunits, cytochrome b2, and the Rieske Fe–S protein; conditional mutants can accumulate insoluble matrix aggregates. (verghese2012biologyofthe pages 29-30)

4) Phenotypes and experimental evidence (selected high-confidence examples)

4.1 Temperature-sensitive mif4 allele and complex behavior

A temperature-sensitive mif4 allele (Gly298→Asp) has been reported to cause the existing ~840 kDa Hsp60 complex to become insoluble within ~2 hours after temperature shift, pelleting at 15,000×g; this phenotype is described in a chaperonin chronologue review synthesizing genetic/biochemical evidence. (horwich2020chaperoninassistedproteinfolding pages 21-21)

4.2 Oxidative stress defense via protection of Fe/S proteins (quantitative)

A primary yeast study engineered strains spanning ~4× Hsp60 overexpression down to ~20% of wild-type (via doxycycline-controlled expression), and found that progressive reduction of Hsp60 reduced viability under oxidative stress while increasing peroxides and protein carbonylation. The same work reports Hsp60 is induced 2–3× at 42°C and that protection of Fe/S enzymes from oxidative inactivation is dose-dependent on Hsp60 levels; reduced Hsp60 increased the labile iron pool (calcein assay), and iron chelation (deferoxamine) partially rescued survival and oxidation phenotypes. (cabiscol2002mitochondrialhsp60resistance pages 1-1)

5) Recent developments (prioritizing 2023–2024)

5.1 2023: New rules for mitochondrial targeting sequences (Hsp60 used as a prototypical precursor)

A 2023 PLOS Genetics study used Hsp60p as a prototypical mitochondrial precursor in targeted MTS mutagenesis and proteome-wide N-terminome analysis. It reports that mitochondrial targeting sequences show favorable determinants including hydrophobic residues at position 2 (notably Leu/Phe/Ile/Trp/Met) and enrichment of Arg at position 3, and proposes that these features balance hydrophobic membrane interaction and positively charged translocation forces for efficient import. This provides a modern, mechanistic framework for annotating Hsp60’s N-terminus as a functional mitochondrial targeting determinant rather than a generic “presequence.” (nashed2023functionalmappingof pages 33-37)

5.2 2023: Environmental/toxicology application—HSP60 as a stress-response readout

A 2023 applied study measured HSP60 in yeast cultures exposed to mycotoxins and found dose- and toxin-dependent responses: a ~2-fold increase in HSP60 at low aflatoxin B2+G1 exposure (12 µg/L), while zearalenone exposure decreased HSP60 (reported as ~12% decrease overall in one excerpt and significant suppression at high dose). The authors emphasize that HSP responses are not systematic and depend on toxin and dose, making HSP60 a context-dependent biomarker of mitochondrial/cellular stress rather than a universally induced marker. (kłosowski2023thereactionof pages 3-6, kłosowski2023thereactionof pages 6-8)

5.3 2024: Updated synthesis of HSP60 mechanism and regulation (contextual, not yeast-specific)

A 2024 review summarizes contemporary understanding of HSP60/HSP10 chaperonin architecture (double ring, lid) and ATP dependence, and notes mechanistic differences reported for mitochondrial HSP60 relative to bacterial GroEL (e.g., nucleotide-state effects on HSP10 binding and single- vs double-ring equilibria). While much of this is framed in mammalian/mitochondrial terms, it provides current expert consensus on mechanistic interpretation relevant to yeast Hsp60 as a Group I mitochondrial chaperonin. (singh2024molecularchaperoninhsp60 pages 4-5, singh2024molecularchaperoninhsp60 pages 2-4)

6) Current applications and real-world implementations

Research applications in yeast (directly supported by retrieved sources):
1. Mitochondrial import engineering / N-terminus design: Hsp60 is used as a model precursor to experimentally test how specific N-terminal residues modulate mitochondrial targeting efficiency and organelle proteome definition. (nashed2023functionalmappingof pages 33-37)
2. Mechanistic mitochondrial oxidative-stress studies: Doxycycline-tunable Hsp60 strains are used to quantify how chaperonin capacity influences oxidative damage, Fe/S enzyme integrity, and iron-mediated toxicity. (cabiscol2002mitochondrialhsp60resistance pages 1-1)
3. Industrial/environmental stress monitoring: HSP60 protein levels can be monitored (immunoblot densitometry) as part of stress-response profiling under chemical contamination (mycotoxins) in aerobic culture. (kłosowski2023thereactionof pages 12-14, kłosowski2023thereactionof pages 3-6)

7) Expert opinions and synthesis (authoritative interpretation)

Authoritative yeast chaperone reviews position Hsp60 as a central mitochondrial matrix folding machine whose loss causes catastrophic proteostasis failure and inviability, with a client range that includes key respiratory and ATP-synthesis components. (verghese2012biologyofthe pages 29-30)

The broader chaperonin field emphasizes that encapsulation-based folding (as opposed to simple “holdase” functions) is an ATP-driven cycle that can actively remodel folding landscapes; this conceptual framework is critical for interpreting yeast Hsp60 phenotypes as failures in mitochondrial biogenesis rather than generalized heat-shock effects. (singh2024molecularchaperoninhsp60 pages 2-4, horwich2020chaperoninassistedproteinfolding pages 2-3)

8) Relevant statistics and quantitative data (from included studies)

Yeast Hsp60-specific quantitative findings:
- 2–3× induction of mitochondrial matrix Hsp60 at 42°C (heat stress). (cabiscol2002mitochondrialhsp60resistance pages 1-1)
- Engineered expression range: ~4× overexpression to ~15–20% of wild-type, enabling graded phenotyping under oxidative stress. (cabiscol2002mitochondrialhsp60resistance pages 1-1, cabiscol2002mitochondrialhsp60resistance pages 3-4)
- Mycotoxin study: ~2-fold HSP60 increase at low aflatoxin B2+G1; ~12% HSP60 decrease with zearalenone exposure (plus significant suppression at high dose). (kłosowski2023thereactionof pages 3-6, kłosowski2023thereactionof pages 6-8)

Network-level quantitative context (not Hsp60-specific but relevant to chaperone biology):
- A quantitative proteomics study estimated chaperones target <40% of proteins but mediate folding of ~62% of total protein flux in the cell, highlighting the global scale of chaperone throughput (Hsp60 included among annotated chaperones, though Hsp60-specific copy number was not extracted in the provided pages). (brownridge2013quantitativeanalysisof pages 1-2, brownridge2013quantitativeanalysisof pages 11-12)

9) Visual evidence (tables/figures)

A yeast chaperone review provides a curated Table of mitochondrial chaperones (including Hsp60/Hsp10) and a schematic overview of the mitochondrial chaperome, placing Hsp60/Hsp10 into the broader protein import/folding network. (verghese2012biologyofthe media ee8d0869, verghese2012biologyofthe media 1b10d921)

Evidence map (summary table)

Evidence focus	Key findings (1-2 sentences)	Study type	Organism/strain	Publication (authors journal year)	Publication date (month/year)	URL	Notes
Identity/localization	Yeast HSP60 corresponds to the mitochondrial matrix chaperonin of the GroEL/Cpn60 family; the ORF is YLR259C and the protein is synthesized as a precursor with an N-terminal targeting presequence cleaved by MPP after residue 21. The mature protein is homologous to GroEL and forms the canonical oligomeric chaperonin assembly in mitochondria. (horwich2020chaperoninassistedproteinfolding pages 21-21)	Review synthesizing primary literature	Saccharomyces cerevisiae	Horwich & Fenton, Quarterly Reviews of Biophysics 2020	Feb 2020	https://doi.org/10.1017/S0033583519000143	572 aa precursor; targeting peptide enriched in Arg/Ser/Thr; essential gene; maps to YLR259C.
Mechanism	Hsp60 is a type I chaperonin that works with Hsp10 as a lid/co-chaperonin in an ATP-dependent folding cycle. In yeast mitochondria it forms a 14-subunit double-ring cavity that transiently binds incompletely folded imported proteins and releases folded products after ATP-driven conformational changes. (verghese2012biologyofthe pages 29-30, singh2024molecularchaperoninhsp60 pages 2-4, singh2024molecularchaperoninhsp60 pages 1-2)	Review	S. cerevisiae; broader conserved eukaryotic/chaperonin comparisons	Verghese et al., Microbiology and Molecular Biology Reviews 2012; Singh et al., International Journal of Molecular Sciences 2024	Jun 2012; May 2024	https://doi.org/10.1128/MMBR.05018-11; https://doi.org/10.3390/ijms25105483	Double heptamer (~14 subunits); substrate capacity ~50 kDa in yeast review; Hsp10/GroES-like lid.
Essentiality/clients	HSP60 is essential for viability in yeast; null mutants are inviable because mitochondrial folding fails. Client examples and affected proteins include imported/matrix proteins such as F1-ATPase subunits, cytochrome b2, and the Rieske FeS protein; conditional mutants accumulate insoluble matrix aggregates. (verghese2012biologyofthe pages 29-30, horwich2020chaperoninassistedproteinfolding pages 20-21)	Review summarizing primary genetics/biochemistry	S. cerevisiae	Verghese et al., Microbiology and Molecular Biology Reviews 2012; Horwich & Fenton, Quarterly Reviews of Biophysics 2020	Jun 2012; Feb 2020	https://doi.org/10.1128/MMBR.05018-11; https://doi.org/10.1017/S0033583519000143	mif4 temperature-sensitive allele (Gly298→Asp) destabilizes the ~840 kDa complex and causes insolubility after heat shift.
Stress/quant data	Hsp60 protein levels rise 2- to 3-fold at 42 °C, and engineered strains spanning ~4× overexpression down to ~20% of wild-type showed that lower Hsp60 reduces oxidative-stress survival and increases peroxides, protein carbonylation, and labile iron. Iron chelation partially rescues low-Hsp60 cells, linking Hsp60 to protection of Fe/S proteins during oxidative stress. (cabiscol2002mitochondrialhsp60resistance pages 1-1, cabiscol2002mitochondrialhsp60resistance pages 3-4)	Primary study	S. cerevisiae (conditional tet-regulated strains)	Cabiscol et al., Journal of Biological Chemistry 2002	Nov 2002	https://doi.org/10.1074/jbc.M206525200	Quantitative values reported in evidence: 4× overexpression; depletion to ~15–20% WT; 2–3× induction at 42 °C; DFO rescue supports iron-dependent damage mechanism.
Recent 2023-2024 developments	A 2023 functional mapping study used Hsp60 as a prototypical mitochondrial precursor and found that specific N-terminal residues in its targeting sequence help define efficient mitochondrial import, with position-2 hydrophobic residues and position-3 Arg highlighted as favorable determinants. A 2024 review further emphasized HSP60/HSP10 complex assembly and ATP-dependent structural transitions as central to mitochondrial proteostasis. (nashed2023functionalmappingof pages 33-37, singh2024molecularchaperoninhsp60 pages 4-5)	Primary (2023) and review (2024)	S. cerevisiae; broader eukaryotic context	Nashed et al., PLOS Genetics 2023; Singh et al., International Journal of Molecular Sciences 2024	Aug 2023; May 2024	https://doi.org/10.1101/2022.08.19.504527; https://doi.org/10.3390/ijms25105483	2023 study identifies Leu/Phe/Ile/Trp/Met enrichment at MTS position 2 and Arg enrichment at position 3; supports import-rule annotation for Hsp60-like precursors.
Recent 2023-2024 developments	In a 2023 applied stress study, yeast HSP60 expression responded to mycotoxins in a dose-dependent, nonuniform way: lower AFB2+AFG1 increased HSP60 by about 2-fold, whereas zearalenone exposure decreased HSP60 (about 12% overall in the cited excerpt; high-dose ZEA significantly suppressed HSP60). These findings reinforce HSP60 as a mitochondrial stress-response readout rather than a universally induced marker. (kłosowski2023thereactionof pages 3-6, kłosowski2023thereactionof pages 12-14, kłosowski2023thereactionof pages 6-8, kłosowski2023thereactionof pages 8-9, kłosowski2023thereactionof pages 2-3)	Primary study	S. cerevisiae Ethanol Red strain	Kłosowski et al., International Journal of Molecular Sciences 2023	Nov 2023	https://doi.org/10.3390/ijms242216401	Conditions in evidence: 72 h aerobic culture; AFB2+AFG1 12 or 36 µg/L, OTA 2.8 or 8.4 µg/L, ZEA 300 or 900 µg/L; significance assessed by ANOVA/Tukey at p < 0.05.
Applications	Hsp60 is useful as a readout and mechanistic node in mitochondrial proteostasis studies, including assays of precursor import determinants, oxidative-stress defense, and environmental toxicology responses in yeast. More broadly, expert reviews position HSP60/HSP10 as a conserved chaperonin system whose dysfunction or altered assembly informs mitochondrial quality-control models and translational disease research. (nashed2023functionalmappingof pages 33-37, cabiscol2002mitochondrialhsp60resistance pages 1-1, singh2024molecularchaperoninhsp60 pages 1-2)	Primary and review	S. cerevisiae; conserved eukaryotic context	Nashed et al., PLOS Genetics 2023; Cabiscol et al., Journal of Biological Chemistry 2002; Singh et al., International Journal of Molecular Sciences 2024	Aug 2023; Nov 2002; May 2024	https://doi.org/10.1101/2022.08.19.504527; https://doi.org/10.1074/jbc.M206525200; https://doi.org/10.3390/ijms25105483	Real-world implementations in the retrieved evidence are research applications, not therapeutics in yeast: import-sequence engineering, oxidative-stress mechanistic tests, and biomarker-like monitoring of toxin responses.

Table: This table summarizes key evidence supporting functional annotation of Saccharomyces cerevisiae HSP60/YLR259C (UniProt P19882), including identity, mechanism, essentiality, stress phenotypes, and recent 2023-2024 developments. It is useful as a compact source map linking major claims to specific studies and quantitative observations.

10) Key source list with URLs and publication dates (most relevant)

Horwich AL, Fenton WA. Chaperonin-assisted protein folding: a chronologue. Feb 2020. https://doi.org/10.1017/S0033583519000143 (horwich2020chaperoninassistedproteinfolding pages 21-21)
Verghese J, Abrams J, Wang Y, Morano KA. Biology of the Heat Shock Response and Protein Chaperones: Budding Yeast as a Model System. Jun 2012. https://doi.org/10.1128/MMBR.05018-11 (verghese2012biologyofthe pages 29-30)
Cabiscol E, Bellí G, Tamarit J, et al. Mitochondrial Hsp60, Resistance to Oxidative Stress, and the Labile Iron Pool Are Closely Connected in S. cerevisiae. Nov 2002. https://doi.org/10.1074/jbc.M206525200 (cabiscol2002mitochondrialhsp60resistance pages 1-1)
Nashed S, El Barbry H, Benchouaia M, et al. Functional mapping of N-terminal residues… mitochondrial protein import. Aug 2023. https://doi.org/10.1101/2022.08.19.504527 (nashed2023functionalmappingof pages 33-37)
Kłosowski G, Koim-Puchowska B, Dróżdż-Afelt J, Mikulski D. Reaction of yeast to mycotoxins… Nov 2023. https://doi.org/10.3390/ijms242216401 (kłosowski2023thereactionof pages 3-6)
Singh MK, Shin Y, Han S, et al. Molecular Chaperonin HSP60: Current Understanding and Future Prospects. May 2024. https://doi.org/10.3390/ijms25105483 (singh2024molecularchaperoninhsp60 pages 2-4)

References

(horwich2020chaperoninassistedproteinfolding pages 21-21): Arthur L. Horwich and Wayne A. Fenton. Chaperonin-assisted protein folding: a chronologue. Quarterly Reviews of Biophysics, Feb 2020. URL: https://doi.org/10.1017/s0033583519000143, doi:10.1017/s0033583519000143. This article has 76 citations and is from a peer-reviewed journal.
(verghese2012biologyofthe pages 29-30): Jacob Verghese, Jennifer Abrams, Yanyu Wang, and Kevin A. Morano. Biology of the heat shock response and protein chaperones: budding yeast (saccharomyces cerevisiae) as a model system. Microbiology and Molecular Biology Reviews, 76:115-158, Jun 2012. URL: https://doi.org/10.1128/mmbr.05018-11, doi:10.1128/mmbr.05018-11. This article has 770 citations and is from a domain leading peer-reviewed journal.
(singh2024molecularchaperoninhsp60 pages 2-4): Manish Kumar Singh, Yoonhwa Shin, Sunhee Han, Joohun Ha, Pramod K. Tiwari, Sung Soo Kim, and Insug Kang. Molecular chaperonin hsp60: current understanding and future prospects. May 2024. URL: https://doi.org/10.3390/ijms25105483, doi:10.3390/ijms25105483. This article has 92 citations.
(singh2024molecularchaperoninhsp60 pages 1-2): Manish Kumar Singh, Yoonhwa Shin, Sunhee Han, Joohun Ha, Pramod K. Tiwari, Sung Soo Kim, and Insug Kang. Molecular chaperonin hsp60: current understanding and future prospects. May 2024. URL: https://doi.org/10.3390/ijms25105483, doi:10.3390/ijms25105483. This article has 92 citations.
(verghese2012biologyofthe pages 26-27): Jacob Verghese, Jennifer Abrams, Yanyu Wang, and Kevin A. Morano. Biology of the heat shock response and protein chaperones: budding yeast (saccharomyces cerevisiae) as a model system. Microbiology and Molecular Biology Reviews, 76:115-158, Jun 2012. URL: https://doi.org/10.1128/mmbr.05018-11, doi:10.1128/mmbr.05018-11. This article has 770 citations and is from a domain leading peer-reviewed journal.
(cabiscol2002mitochondrialhsp60resistance pages 1-1): Elisa Cabiscol, Gemma Bellı́, Jordi Tamarit, Pedro Echave, Enrique Herrero, and Joaquim Ros. Mitochondrial hsp60, resistance to oxidative stress, and the labile iron pool are closely connected in saccharomyces cerevisiae *. The Journal of Biological Chemistry, 277:44531-44538, Nov 2002. URL: https://doi.org/10.1074/jbc.m206525200, doi:10.1074/jbc.m206525200. This article has 168 citations.
(nashed2023functionalmappingof pages 33-37): Salomé Nashed, Houssam El Barbry, Médine Benchouaia, Angélie Dijoux-Maréchal, T. Delaveau, Nadia Ruiz-Gutierrez, Lucie Gaulier, D. Tribouillard-Tanvier, Guillaume Chevreux, S. Le Crom, Benoît Palancade, F. Devaux, É. Laine, and Mathilde Garcia. Functional mapping of n-terminal residues in the yeast proteome uncovers novel determinants for mitochondrial protein import. PLOS Genetics, Aug 2023. URL: https://doi.org/10.1101/2022.08.19.504527, doi:10.1101/2022.08.19.504527. This article has 5 citations and is from a domain leading peer-reviewed journal.
(kłosowski2023thereactionof pages 3-6): Grzegorz Kłosowski, Beata Koim-Puchowska, Joanna Dróżdż-Afelt, and Dawid Mikulski. The reaction of the yeast saccharomyces cerevisiae to contamination of the medium with aflatoxins b2 and g1, ochratoxin a and zearalenone in aerobic cultures. International Journal of Molecular Sciences, 24:16401, Nov 2023. URL: https://doi.org/10.3390/ijms242216401, doi:10.3390/ijms242216401. This article has 9 citations.
(kłosowski2023thereactionof pages 6-8): Grzegorz Kłosowski, Beata Koim-Puchowska, Joanna Dróżdż-Afelt, and Dawid Mikulski. The reaction of the yeast saccharomyces cerevisiae to contamination of the medium with aflatoxins b2 and g1, ochratoxin a and zearalenone in aerobic cultures. International Journal of Molecular Sciences, 24:16401, Nov 2023. URL: https://doi.org/10.3390/ijms242216401, doi:10.3390/ijms242216401. This article has 9 citations.
(singh2024molecularchaperoninhsp60 pages 4-5): Manish Kumar Singh, Yoonhwa Shin, Sunhee Han, Joohun Ha, Pramod K. Tiwari, Sung Soo Kim, and Insug Kang. Molecular chaperonin hsp60: current understanding and future prospects. May 2024. URL: https://doi.org/10.3390/ijms25105483, doi:10.3390/ijms25105483. This article has 92 citations.
(kłosowski2023thereactionof pages 12-14): Grzegorz Kłosowski, Beata Koim-Puchowska, Joanna Dróżdż-Afelt, and Dawid Mikulski. The reaction of the yeast saccharomyces cerevisiae to contamination of the medium with aflatoxins b2 and g1, ochratoxin a and zearalenone in aerobic cultures. International Journal of Molecular Sciences, 24:16401, Nov 2023. URL: https://doi.org/10.3390/ijms242216401, doi:10.3390/ijms242216401. This article has 9 citations.
(horwich2020chaperoninassistedproteinfolding pages 2-3): Arthur L. Horwich and Wayne A. Fenton. Chaperonin-assisted protein folding: a chronologue. Quarterly Reviews of Biophysics, Feb 2020. URL: https://doi.org/10.1017/s0033583519000143, doi:10.1017/s0033583519000143. This article has 76 citations and is from a peer-reviewed journal.
(cabiscol2002mitochondrialhsp60resistance pages 3-4): Elisa Cabiscol, Gemma Bellı́, Jordi Tamarit, Pedro Echave, Enrique Herrero, and Joaquim Ros. Mitochondrial hsp60, resistance to oxidative stress, and the labile iron pool are closely connected in saccharomyces cerevisiae *. The Journal of Biological Chemistry, 277:44531-44538, Nov 2002. URL: https://doi.org/10.1074/jbc.m206525200, doi:10.1074/jbc.m206525200. This article has 168 citations.
(brownridge2013quantitativeanalysisof pages 1-2): Philip Brownridge, Craig Lawless, Aishwarya B. Payapilly, Karin Lanthaler, Stephen W. Holman, Victoria M. Harman, Christopher M. Grant, Robert J. Beynon, and Simon J. Hubbard. Quantitative analysis of chaperone network throughput in budding yeast. Proteomics, 13:1276-1291, Mar 2013. URL: https://doi.org/10.1002/pmic.201200412, doi:10.1002/pmic.201200412. This article has 43 citations and is from a peer-reviewed journal.
(brownridge2013quantitativeanalysisof pages 11-12): Philip Brownridge, Craig Lawless, Aishwarya B. Payapilly, Karin Lanthaler, Stephen W. Holman, Victoria M. Harman, Christopher M. Grant, Robert J. Beynon, and Simon J. Hubbard. Quantitative analysis of chaperone network throughput in budding yeast. Proteomics, 13:1276-1291, Mar 2013. URL: https://doi.org/10.1002/pmic.201200412, doi:10.1002/pmic.201200412. This article has 43 citations and is from a peer-reviewed journal.
(verghese2012biologyofthe media ee8d0869): Jacob Verghese, Jennifer Abrams, Yanyu Wang, and Kevin A. Morano. Biology of the heat shock response and protein chaperones: budding yeast (saccharomyces cerevisiae) as a model system. Microbiology and Molecular Biology Reviews, 76:115-158, Jun 2012. URL: https://doi.org/10.1128/mmbr.05018-11, doi:10.1128/mmbr.05018-11. This article has 770 citations and is from a domain leading peer-reviewed journal.
(verghese2012biologyofthe media 1b10d921): Jacob Verghese, Jennifer Abrams, Yanyu Wang, and Kevin A. Morano. Biology of the heat shock response and protein chaperones: budding yeast (saccharomyces cerevisiae) as a model system. Microbiology and Molecular Biology Reviews, 76:115-158, Jun 2012. URL: https://doi.org/10.1128/mmbr.05018-11, doi:10.1128/mmbr.05018-11. This article has 770 citations and is from a domain leading peer-reviewed journal.
(horwich2020chaperoninassistedproteinfolding pages 20-21): Arthur L. Horwich and Wayne A. Fenton. Chaperonin-assisted protein folding: a chronologue. Quarterly Reviews of Biophysics, Feb 2020. URL: https://doi.org/10.1017/s0033583519000143, doi:10.1017/s0033583519000143. This article has 76 citations and is from a peer-reviewed journal.
(kłosowski2023thereactionof pages 8-9): Grzegorz Kłosowski, Beata Koim-Puchowska, Joanna Dróżdż-Afelt, and Dawid Mikulski. The reaction of the yeast saccharomyces cerevisiae to contamination of the medium with aflatoxins b2 and g1, ochratoxin a and zearalenone in aerobic cultures. International Journal of Molecular Sciences, 24:16401, Nov 2023. URL: https://doi.org/10.3390/ijms242216401, doi:10.3390/ijms242216401. This article has 9 citations.
(kłosowski2023thereactionof pages 2-3): Grzegorz Kłosowski, Beata Koim-Puchowska, Joanna Dróżdż-Afelt, and Dawid Mikulski. The reaction of the yeast saccharomyces cerevisiae to contamination of the medium with aflatoxins b2 and g1, ochratoxin a and zearalenone in aerobic cultures. International Journal of Molecular Sciences, 24:16401, Nov 2023. URL: https://doi.org/10.3390/ijms242216401, doi:10.3390/ijms242216401. This article has 9 citations.

Artifacts

Edison artifact artifact-00

Citations

horwich2020chaperoninassistedproteinfolding pages 21-21
verghese2012biologyofthe pages 29-30
nashed2023functionalmappingof pages 33-37
verghese2012biologyofthe pages 26-27
horwich2020chaperoninassistedproteinfolding pages 2-3
brownridge2013quantitativeanalysisof pages 1-2
brownridge2013quantitativeanalysisof pages 11-12
horwich2020chaperoninassistedproteinfolding pages 20-21
https://doi.org/10.1017/S0033583519000143
https://doi.org/10.1128/MMBR.05018-11;
https://doi.org/10.3390/ijms25105483
https://doi.org/10.1074/jbc.M206525200
https://doi.org/10.1101/2022.08.19.504527;
https://doi.org/10.3390/ijms242216401
https://doi.org/10.1074/jbc.M206525200;
https://doi.org/10.1128/MMBR.05018-11
https://doi.org/10.1101/2022.08.19.504527
https://doi.org/10.1017/s0033583519000143,
https://doi.org/10.1128/mmbr.05018-11,
https://doi.org/10.3390/ijms25105483,
https://doi.org/10.1074/jbc.m206525200,
https://doi.org/10.1101/2022.08.19.504527,
https://doi.org/10.3390/ijms242216401,
https://doi.org/10.1002/pmic.201200412,

📚 Additional Documentation

Bioreason Rl Predictions

(HSP60-bioreason-rl-predictions.md)

BioReason Chat Export

Exported on March 22, 2026 at 01:58 AM

Organism: Saccharomyces cerevisiae

Sequence:

MLRSSVVRSRATLRPLLRRAYSSHKELKFGVEGRASLLKGVETLAEAVAATLGPKGRNVLIEQPFGPPKITKDGVTVAKSIVLKDKFENMGAKLLQEVASKTNEAAGDGTTSATVLGRAIFTESVKNVAAGCNPMDLRRGSQVAVEKVIEFLSANKKEITTSEEIAQVATISANGDSHVGKLLASAMEKVGKEGVITIREGRTLEDELEVTEGMRFDRGFISPYFITDPKSSKVEFEKPLLLLSEKKISSIQDILPALEISNQSRRPLLIIAEDVDGEALAACILNKLRGQVKVCAVKAPGFGDNRKNTIGDIAVLTGGTVFTEELDLKPEQCTIENLGSCDSITVTKEDTVILNGSGPKEAIQERIEQIKGSIDITTTNSYEKEKLQERLAKLSGGVAVIRVGGASEVEVGEKKDRYDDALNATRAAVEEGILPGGGTALVKASRVLDEVVVDNFDQKLGVDIIRKAITRPAKQIIENAGEEGSVIIGKLIDEYGDDFAKGYDASKSEYTDMLATGIIDPFKVVRSGLVDASGVASLLATTEVAIVDAPEPPAAAGAGGMPGGMPGMPGMM

Thinking Trace

I begin with the InterPro architecture. The sequence is dominated by IPR001844 (Chaperonin Cpn60/GroEL family, residues 21–568) and IPR002423 (Chaperonin Cpn60/GroEL/TCP-1 family, residues 44–544), establishing a canonical group I chaperonin scaffold that assembles into double-ring oligomers. This scaffold is refined by three superfamily signatures that map the mechanistic subdomains: IPR027413 (GroEL-like equatorial domain superfamily, residues 27–547) encodes the ATPase core and inter-ring contacts; IPR027410 (TCP-1-like chaperonin intermediate domain superfamily, residues 158–432) forms the hinge that transduces nucleotide-state changes; and IPR027409 (GroEL-like apical domain superfamily, residues 205–398) shapes the substrate-binding cavity and ring closure. A conserved catalytic/structural patch is pinpointed by IPR018370 (Chaperonin Cpn60 conserved site, residues 427–438), which stabilizes the equatorial fold and supports ATP-coupled conformational cycling. The ordered layout—equatorial ATPase base, movable intermediate hinge, and apical substrate-facing crown—causes ATP-driven folding cycles characteristic of group I chaperonins.

From this architecture, the molecular function follows. The equatorial domain’s nucleotide pocket and the conserved site together impose ATP hydrolysis that powers conformational transitions; thus ATP binding and ATPase activity are intrinsic. The apical domain’s hydrophobic cavity binds non-native polypeptides, enabling transient holdase and foldase actions. This mechanistic ensemble supports GO:0003824 molecular function by providing ATP-dependent chaperone activity that captures and releases unfolded proteins.

These chaperone cycles drive the biological process of protein folding and refolding. By encapsulating client proteins within a nano-cage and timing their release with ATP hydrolysis, the complex executes GO:0009987 cellular process roles tied to proteostasis—restoring native structure after stress and preventing aggregation. The ring-switch mechanism explains how folding fidelity is achieved through iterative encapsulation and nucleotide-gated ring closure.

Cellular location emerges from the absence of signal peptides or transmembrane segments and the soluble, cytosolic nature of group I chaperonins in yeast. The oligomer operates in the cytoplasm, aligning with the stated subcellular location and supporting a cytosolic folding hub that services nascent chains and stress-denatured proteins.

Mechanistically, I hypothesize that this chaperonin forms heptameric rings that dimerize into a double-hexamer. ATP binding at the equatorial domains triggers allosteric transitions propagated via the intermediate hinge, closing the apical lids to encapsulate clients. Likely interaction partners include nascent polypeptide-associated factors and ribosome-proximal chaperones that deliver substrates, as well as small heat shock proteins that pre-hold clients upstream. Together, these assemblies coordinate substrate handoff, encapsulation, and productive folding cycles in the cytoplasm.

Functional Summary

A cytosolic group I chaperonin that assembles into a double-ring nano-cage to assist ATP-dependent folding of unfolded and misfolded proteins. Its equatorial ATPase core drives conformational cycles that are transmitted through an intermediate hinge to apical substrate-binding surfaces, enabling transient capture and encapsulation of clients for productive refolding in the cytoplasm. By coupling nucleotide hydrolysis to lid closure and release, it sustains cellular proteostasis and restores native structures after stress.

UniProt Summary

Chaperonin involved in assist free passage of proteins through the channels of the mitochondrial translocation machinery.

InterPro Domains

Chaperonin Cpn60/GroEL (IPR001844, family) — residues 21-568
GroEL-like equatorial domain superfamily (IPR027413, homologous_superfamily) — residues 27-547
Chaperonin Cpn60/GroEL/TCP-1 family (IPR002423, family) — residues 44-544
TCP-1-like chaperonin intermediate domain superfamily (IPR027410, homologous_superfamily) — residues 158-432
GroEL-like apical domain superfamily (IPR027409, homologous_superfamily) — residues 205-398
Chaperonin Cpn60, conserved site (IPR018370, conserved_site) — residues 427-438

GO Terms

Molecular Function: molecular_function (GO:0003674), binding (GO:0005488), GO:0016887 (GO:0003824), ATP-dependent activity (GO:0140657), ATP hydrolysis activity (GO:0016887), heterocyclic compound binding (GO:1901363), hydrolase activity (GO:0016787), organic cyclic compound binding (GO:0097159), protein binding (GO:0005515), nucleic acid binding (GO:0003676), hydrolase activity, acting on acid anhydrides (GO:0016817), chaperone binding (GO:0051087), unfolded protein binding (GO:0051082), DNA binding (GO:0003677), hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides (GO:0016818), pyrophosphatase activity (GO:0016462), double-stranded DNA binding (GO:0003690), sequence-specific DNA binding (GO:0043565), single-stranded DNA binding (GO:0003697), sequence-specific double-stranded DNA binding (GO:1990837), ribonucleoside triphosphate phosphatase activity (GO:0017111), DNA replication origin binding (GO:0003688)

Biological Process: biological_process (GO:0008150), metabolic process (GO:0008152), biological regulation (GO:0065007), localization (GO:0051179), GO:0006457 (GO:0009987), regulation of biological quality (GO:0065008), cellular localization (GO:0051641), transmembrane transport (GO:0055085), nitrogen compound metabolic process (GO:0006807), protein folding (GO:0006457), establishment of localization (GO:0051234), cellular component organization or biogenesis (GO:0071840), organic substance metabolic process (GO:0071704), primary metabolic process (GO:0044238), macromolecule localization (GO:0033036), cellular component biogenesis (GO:0044085), organonitrogen compound metabolic process (GO:1901564), intracellular transport (GO:0046907), protein refolding (GO:0042026), protein transmembrane transport (GO:0071806), protein metabolic process (GO:0019538), transport (GO:0006810), mitochondrial transmembrane transport (GO:1990542), cellular macromolecule localization (GO:0070727), establishment of localization in cell (GO:0051649), cellular component organization (GO:0016043), regulation of protein stability (GO:0031647), 'de novo' protein folding (GO:0006458), macromolecule metabolic process (GO:0043170), establishment of protein localization (GO:0045184), mitochondrial transport (GO:0006839), intracellular protein transport (GO:0006886), nitrogen compound transport (GO:0071705), protein transport (GO:0015031), establishment of protein localization to organelle (GO:0072594), protein maturation (GO:0051604), organic substance transport (GO:0071702), intracellular protein transmembrane transport (GO:0065002), protein stabilization (GO:0050821), protein-containing complex organization (GO:0043933), protein localization (GO:0008104), protein transmembrane import into intracellular organelle (GO:0044743), organelle organization (GO:0006996), gene expression (GO:0010467), cellular component assembly (GO:0022607), establishment of protein localization to mitochondrion (GO:0072655), mitochondrion organization (GO:0007005), protein localization to organelle (GO:0033365), protein targeting (GO:0006605), protein-containing complex assembly (GO:0065003), protein targeting to mitochondrion (GO:0006626), protein localization to mitochondrion (GO:0070585), chaperone-mediated protein complex assembly (GO:0051131)

Cellular Component: cellular_component (GO:0005575), cellular anatomical entity (GO:0110165), intracellular anatomical structure (GO:0005622), organelle (GO:0043226), GO:0005737 (GO:0016020), cytosol (GO:0005829), nucleoid (GO:0009295), envelope (GO:0031975), cytoplasm (GO:0005737), membrane-enclosed lumen (GO:0031974), organelle membrane (GO:0031090), organelle envelope (GO:0031967), intracellular organelle (GO:0043229), non-membrane-bounded organelle (GO:0043228), mitochondrion (GO:0005739), organelle lumen (GO:0043233), mitochondrial nucleoid (GO:0042645), membrane-bounded organelle (GO:0043227), mitochondrial envelope (GO:0005740), intracellular membrane-bounded organelle (GO:0043231), organelle envelope lumen (GO:0031970), intracellular non-membrane-bounded organelle (GO:0043232), organelle inner membrane (GO:0019866), mitochondrial matrix (GO:0005759), intracellular organelle lumen (GO:0070013), mitochondrial membrane (GO:0031966), mitochondrial intermembrane space (GO:0005758), mitochondrial inner membrane (GO:0005743)

Generated by BioReason

Bioreason Rl Review

(HSP60-bioreason-rl-review.md)

BioReason-Pro RL Review: HSP60 (S. cerevisiae)

Source: HSP60-bioreason-rl-predictions.md

Correctness: 3/5
Completeness: 2/5

Functional Summary Review

The BioReason summary states:

A cytosolic group I chaperonin that assembles into a double-ring nano-cage to assist ATP-dependent folding of unfolded and misfolded proteins.

The identification as a group I chaperonin with double-ring architecture and ATP-dependent folding is correct. However, the claim of "cytosolic" localization is a significant error. HSP60 is a mitochondrial matrix protein (GO:0005759), as confirmed by the curated review: "HSP60 is a mitochondrial group I chaperonin (GroEL homolog) that forms a tetradecameric double-ring complex in the mitochondrial matrix." Multiple experimental references support this (PMID:2645524, PMID:11502169).

Its equatorial ATPase core drives conformational cycles that are transmitted through an intermediate hinge to apical substrate-binding surfaces, enabling transient capture and encapsulation of clients for productive refolding in the cytoplasm.

The mechanistic description of the chaperonin cycle (equatorial ATPase, intermediate hinge, apical substrate-binding) is structurally accurate. But again, "in the cytoplasm" is wrong -- it should be "in the mitochondrial matrix."

By coupling nucleotide hydrolysis to lid closure and release, it sustains cellular proteostasis and restores native structures after stress.

This is generically correct but misses the specific biological context. The curated review documents: folding of newly imported mitochondrial proteins (the primary function), roles in mtDNA maintenance as a component of mitochondrial nucleoids (PMID:14597775), single-stranded DNA binding and replication origin binding (GO:0003697, GO:0003688), cooperation with co-chaperonin HSP10, and the essential self-assembly requirement.

Notably, the UniProt summary itself states "assist free passage of proteins through the channels of the mitochondrial translocation machinery," directly pointing to mitochondrial localization, which BioReason appears to have ignored.

Comparison with interpro2go:

BioReason's GO term predictions include mitochondrion (GO:0005739), mitochondrial matrix (GO:0005759), and mitochondrial inner membrane (GO:0005743) in the CC section -- yet the functional summary claims cytosolic localization. This is an internal inconsistency: the GO term predictions are more accurate than the prose summary. The interpro2go predictions correctly place the protein in the mitochondrion. BioReason's MF predictions include DNA binding terms (GO:0003677, GO:0003690, GO:0003697, GO:0003688) which are actually documented functions of yeast HSP60 per the curated review -- but the summary does not mention DNA binding at all.

Notes on thinking trace

The trace states: "The cellular component is inferred from the absence of signal peptides or transmembrane segments and the soluble, cytosolic nature of group I chaperonins in yeast." This reveals the key failure: the model defaults to cytosolic localization for soluble proteins, failing to recognize that mitochondrial matrix proteins have cleavable signal peptides that are removed post-import. The N-terminal mitochondrial targeting sequence is actually present in the precursor but absent from the mature protein.

📄 View Raw YAML

id: P19882
gene_symbol: HSP60
product_type: PROTEIN
status: DRAFT
aliases:
- MIF4
- YLR259C
- CPN60
- P66
taxon:
  id: NCBITaxon:559292
  label: Saccharomyces cerevisiae S288C
description: >-
  HSP60 is a mitochondrial group I chaperonin (GroEL homolog) that forms a
  tetradecameric double-ring complex in the mitochondrial matrix. It is an
  essential ATP-dependent protein folding machine that assists the folding
  of newly imported proteins after they are translocated into the
  mitochondrial matrix. HSP60 binds unfolded or partially folded polypeptides
  inside its central cavity and, in cooperation with its co-chaperonin HSP10,
  mediates ATP-dependent folding. HSP60 also protects pre-existing proteins
  against heat denaturation by binding them during thermal stress and mediating
  their refolding. Additionally, HSP60 plays roles in mtDNA maintenance as a
  component of mitochondrial nucleoids, where it binds single-stranded DNA
  and replication origins. HSP60 is required for its own assembly, as newly
  imported monomers require pre-existing functional HSP60 complex for oligomerization.
existing_annotations:
- term:
    id: GO:0006457
    label: protein folding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Phylogenetic inference is well supported. HSP60 is a group I chaperonin whose primary function is protein folding in the mitochondrial matrix. PMID:2645524 showed HSP60 is essential for assembly of imported proteins, and PMID:1978929 demonstrated it is required for its own de novo folding.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:2645524
      supporting_text: Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria.
    - reference_id: PMID:1978929
      supporting_text: Hsp60 monomers form a complex arranged as two stacked 7-mer rings. This 14-mer complex binds unfolded proteins at its surface, then seems to catalyse their folding in an ATP-dependent process.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        In yeast specifically, Hsp60 forms a **14-subunit double-ring (two heptameric rings)**, creating a cavity that can accommodate client proteins up to ~**50 kDa**, and imported precursor proteins transiently associate with Hsp60 as incompletely folded intermediates before ATP-dependent folding/release.
- term:
    id: GO:0007005
    label: mitochondrion organization
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Phylogenetic inference is supported by experimental evidence. HSP60 is essential for mitochondrial biogenesis; loss-of-function mutants show defects in mitochondrial protein assembly and mtDNA maintenance (PMID:2645524, PMID:14597775).
    action: ACCEPT
    supported_by:
    - reference_id: PMID:2645524
      supporting_text: Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria.
    - reference_id: PMID:14597775
      supporting_text: A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        HSP60 is **essential for viability**: deletion/null mutants are inviable due to severe mitochondrial folding defects.
- term:
    id: GO:0005743
    label: mitochondrial inner membrane
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: HSP60 is primarily a soluble matrix protein. There is some association with the inner membrane, possibly through its role in the TIM23-PAM import machinery, but the primary active location is the mitochondrial matrix. This IBA annotation is acceptable as HSP60 may be active at the inner membrane during protein import.
    action: KEEP_AS_NON_CORE
    reason: HSP60 is primarily a matrix protein; inner membrane association is secondary to its import-related functions.
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Phylogenetic inference consistent with UniProt annotation (PMID:11502169) and experimental localization data. The mitochondrial matrix is the primary location where HSP60 functions.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:11502169
      supporting_text: Yeast mitochondrial dehydrogenases are associated in a supramolecular complex.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        Yeast Hsp60 is produced as a **mitochondrial precursor** with an N-terminal matrix-targeting presequence, cleaved by MPP after residue 21, consistent with mitochondrial import and processing to a mature matrix protein.
- term:
    id: GO:0034514
    label: mitochondrial unfolded protein response
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Phylogenetic inference. HSP60 expression is induced by mitochondrial stress and heat shock. As a major mitochondrial chaperonin, it is a key effector of the mitochondrial unfolded protein response. This is a secondary/responsive function rather than core enzymatic activity.
    action: KEEP_AS_NON_CORE
    reason: This is a stress response pathway annotation; the core function is ATP-dependent protein folding.
- term:
    id: GO:0045041
    label: protein import into mitochondrial intermembrane space
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Phylogenetic inference supported by experimental evidence from PMID:1347713, which demonstrated that HSP60 couples protein import into the matrix with export to the intermembrane space.
    action: KEEP_AS_NON_CORE
    reason: This is a secondary function of HSP60 related to its role in the TIM23/PAM import pathway; the core function is protein folding in the matrix.
    supported_by:
    - reference_id: PMID:1347713
      supporting_text: Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space.
- term:
    id: GO:0051087
    label: protein-folding chaperone binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Phylogenetic inference supported by direct experimental evidence. PMID:9256426 demonstrated physical interaction between HSP60 and HSP10 (co-chaperonin) with measured binding constants (Kd 0.9 nM in ADP).
    action: ACCEPT
    supported_by:
    - reference_id: PMID:9256426
      supporting_text: In the presence of ADP, one molecule of hsp10 binds to hsp60 with an apparent Kd of 0.9 nM and a second molecule of hsp10 binds with a Kd of 24 nM.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        the co-chaperonin **Hsp10 (GroES-like)** caps the cavity (“lid”), enabling an encapsulated folding environment; ATP hydrolysis and nucleotide exchange govern release/reset.
- term:
    id: GO:0000166
    label: nucleotide binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: Overly general IEA annotation based on UniProt keyword. HSP60 specifically binds ATP; the more specific term GO:0005524 (ATP binding) is already annotated.
    action: MODIFY
    reason: Too general; ATP binding is the correct specific term.
    proposed_replacement_terms:
    - id: GO:0005524
      label: ATP binding
- term:
    id: GO:0005524
    label: ATP binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: IEA annotation consistent with HSP60 being an ATPase chaperonin. HSP60 binds and hydrolyzes ATP as part of its folding cycle. Supported by direct assay in PMID:7902576 and PMID:9256426.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:7902576
      supporting_text: Identification and functional analysis of chaperonin 10, the groES homolog from yeast mitochondria.
    - reference_id: PMID:9256426
      supporting_text: Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: |-
      ARBA machine learning annotation. HSP60 is synthesized in the cytoplasm as a precursor but its functional location is the mitochondrial matrix. This annotation is misleading as it does not reflect the active location of the protein. Falcon notes that a small extra-mitochondrial pool (~15-20% cytoplasmic) has been reported for HSP60 in higher eukaryotes, but explicitly flags this distribution as "not yeast-specific", so it does not justify a yeast cytoplasm annotation.
    action: REMOVE
    reason: HSP60 is a mitochondrial matrix protein. Cytoplasmic presence is only transient during import; the reported cytoplasmic pool is from mammalian studies, not yeast.
    supported_by:
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        In broader eukaryotic contexts, HSP60 is predominantly mitochondrial and can also be detected in extra-mitochondrial compartments; one 2024 review summarizes a distribution of ~**80–85% mitochondrial** and ~**15–20% cytoplasmic** for HSP60 (not yeast-specific).
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: IEA annotation based on UniProt subcellular location. Consistent with IBA and experimental evidence. Redundant with IBA annotation but correct.
    action: ACCEPT
- term:
    id: GO:0006457
    label: protein folding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: InterPro-based IEA annotation. Redundant with IBA and IMP evidence for the same term, but correct.
    action: ACCEPT
- term:
    id: GO:0042026
    label: protein refolding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: InterPro-based IEA annotation. Consistent with experimental evidence from PMID:1359644 and PMID:9256426 showing HSP60 mediates ATP-dependent refolding of denatured proteins.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:1359644
      supporting_text: Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
    - reference_id: PMID:9256426
      supporting_text: In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
- term:
    id: GO:0051082
    label: unfolded protein binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: GO:0051082 is proposed for obsoletion. HSP60 is an ATP-dependent group I chaperonin (foldase) that actively folds proteins, not merely a passive binding protein. The correct term is GO:0140662 (ATP-dependent protein folding chaperone).
    action: MODIFY
    reason: GO:0051082 is proposed for obsoletion. HSP60 is a bona fide ATP-dependent foldase chaperonin, not a passive unfolded protein binder.
    proposed_replacement_terms:
    - id: GO:0140662
      label: ATP-dependent protein folding chaperone
- term:
    id: GO:0140662
    label: ATP-dependent protein folding chaperone
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: This is the correct and most informative molecular function term for HSP60. It is a group I chaperonin that uses ATP hydrolysis to fold substrate proteins within its central cavity. Supported by PMID:7902576 (ATPase activity), PMID:9256426 (ATP-dependent refolding of malate dehydrogenase), and PMID:1359644 (ATP-dependent refolding of DHFR).
    action: ACCEPT
    reason: This is the primary molecular function of HSP60 and the correct replacement for GO:0051082.
    supported_by:
    - reference_id: PMID:9256426
      supporting_text: In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
    - reference_id: PMID:1359644
      supporting_text: Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        ATP-dependent **protein folding chaperonin** for mitochondrial matrix proteins, particularly those imported into mitochondria as unfolded precursors.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        Hsp60 does not catalyze a chemical transformation of a small molecule substrate; rather, it catalyzes **conformational maturation of polypeptides** by providing a protected folding environment and coordinating binding/release with ATP hydrolysis and Hsp10 capping.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:11805837
  review:
    summary: High-throughput mass spectrometry identification of protein complexes. Protein binding is uninformative for a chaperonin that interacts with many client proteins. The binding reflects chaperone-client interactions.
    action: MARK_AS_OVER_ANNOTATED
    reason: Protein binding is uninformative for a chaperonin; its binding to clients is part of its ATP-dependent protein folding chaperone activity.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16429126
  review:
    summary: Same rationale as above. Protein binding is uninformative for a chaperonin.
    action: MARK_AS_OVER_ANNOTATED
    reason: Protein binding is uninformative for a chaperonin.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16554755
  review:
    summary: Same rationale as above. Protein binding is uninformative for a chaperonin.
    action: MARK_AS_OVER_ANNOTATED
    reason: Protein binding is uninformative for a chaperonin.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19536198
  review:
    summary: Chaperone-protein interaction atlas. Protein binding is uninformative for a chaperonin.
    action: MARK_AS_OVER_ANNOTATED
    reason: Protein binding is uninformative for a chaperonin.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:37968396
  review:
    summary: Same rationale as above.
    action: MARK_AS_OVER_ANNOTATED
    reason: Protein binding is uninformative for a chaperonin.
- term:
    id: GO:0042645
    label: mitochondrial nucleoid
  evidence_type: IDA
  original_reference_id: PMID:14597775
  review:
    summary: Direct experimental evidence showing HSP60 localizes to mitochondrial nucleoids. PMID:14597775 demonstrated a function for HSP60 in the structure and transmission of mtDNA nucleoids.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:14597775
      supporting_text: A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae.
- term:
    id: GO:0051082
    label: unfolded protein binding
  evidence_type: IMP
  original_reference_id: PMID:1359644
  review:
    summary: PMID:1359644 showed that HSP60 forms complexes with polypeptides in organelles exposed to heat stress and mediates ATP-dependent refolding. This is active chaperonin-mediated folding, not passive unfolded protein binding. The correct term is GO:0140662 (ATP-dependent protein folding chaperone).
    action: MODIFY
    reason: GO:0051082 is proposed for obsoletion. The experiment demonstrates ATP-dependent chaperonin folding activity, which is GO:0140662.
    proposed_replacement_terms:
    - id: GO:0140662
      label: ATP-dependent protein folding chaperone
    supported_by:
    - reference_id: PMID:1359644
      supporting_text: Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: HDA
  original_reference_id: PMID:24769239
  review:
    summary: High-throughput proteomics of mitochondria. Consistent with known localization. Less specific than mitochondrial matrix but correct.
    action: KEEP_AS_NON_CORE
    reason: Correct but less specific than mitochondrial matrix.
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: HDA
  original_reference_id: PMID:14576278
  review:
    summary: Mitochondrial proteomics. Consistent with known localization.
    action: KEEP_AS_NON_CORE
    reason: Correct but less specific than mitochondrial matrix.
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: HDA
  original_reference_id: PMID:16823961
  review:
    summary: Mitochondrial proteomics. Consistent with known localization.
    action: KEEP_AS_NON_CORE
    reason: Correct but less specific than mitochondrial matrix.
- term:
    id: GO:0003688
    label: DNA replication origin binding
  evidence_type: IDA
  original_reference_id: PMID:10869431
  review:
    summary: PMID:10869431 used in organello formaldehyde crosslinking to identify HSP60 as a bifunctional protein that binds mtDNA replication origins. This is a secondary moonlighting function related to mtDNA maintenance, not the core protein folding function.
    action: KEEP_AS_NON_CORE
    reason: This is a moonlighting function related to mtDNA nucleoid maintenance, distinct from the core chaperonin folding activity.
    supported_by:
    - reference_id: PMID:10869431
      supporting_text: "In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins."
- term:
    id: GO:0003697
    label: single-stranded DNA binding
  evidence_type: IDA
  original_reference_id: PMID:10869431
  review:
    summary: Same paper as DNA replication origin binding. HSP60 was shown to bind ssDNA in the context of mtDNA nucleoid maintenance. This is a moonlighting function.
    action: KEEP_AS_NON_CORE
    reason: Moonlighting function related to mtDNA maintenance; not the core chaperonin activity.
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: IDA
  original_reference_id: PMID:11502169
  review:
    summary: Direct experimental evidence of mitochondrial localization from protein sequencing study.
    action: KEEP_AS_NON_CORE
    reason: Correct but less specific than mitochondrial matrix.
- term:
    id: GO:0005739
    label: mitochondrion
  evidence_type: IDA
  original_reference_id: PMID:8097278
  review:
    summary: Direct experimental evidence of mitochondrial localization. PMID:8097278 studied loss of mitochondrial hsp60 function.
    action: KEEP_AS_NON_CORE
    reason: Correct but less specific than mitochondrial matrix.
- term:
    id: GO:0006458
    label: "'de novo' protein folding"
  evidence_type: IMP
  original_reference_id: PMID:1978929
  review:
    summary: PMID:1978929 demonstrated that HSP60 is required for its own assembly - newly imported HSP60 monomers require functional pre-existing HSP60 complex to fold and assemble into the tetradecamer. This is direct evidence for de novo protein folding activity.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:1978929
      supporting_text: Functional pre-existing hsp60 complex is required in order to form new, assembled, 14-mer. Subunits imported in vitro are assembled with a surprisingly fast half-time of 5-10 min, indicative of a catalysed reaction.
- term:
    id: GO:0016887
    label: ATP hydrolysis activity
  evidence_type: IDA
  original_reference_id: PMID:7902576
  review:
    summary: PMID:7902576 directly measured ATPase activity of yeast HSP60 (cpn60). The ATPase activity is intrinsic to the chaperonin folding cycle.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:7902576
      supporting_text: Identification and functional analysis of chaperonin 10, the groES homolog from yeast mitochondria.
    - reference_id: PMID:9256426
      supporting_text: Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
- term:
    id: GO:0016887
    label: ATP hydrolysis activity
  evidence_type: IDA
  original_reference_id: PMID:9256426
  review:
    summary: PMID:9256426 demonstrated that HSP60 has ATPase activity that is inhibited approximately 40% by HSP10. This inhibition is mechanistically coupled to the folding cycle.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:9256426
      supporting_text: Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
- term:
    id: GO:0042026
    label: protein refolding
  evidence_type: IMP
  original_reference_id: PMID:1359644
  review:
    summary: PMID:1359644 showed HSP60 mediates ATP-dependent refolding of heat-denatured DHFR in vitro, preventing aggregation and restoring activity.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:1359644
      supporting_text: Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
- term:
    id: GO:0042026
    label: protein refolding
  evidence_type: IDA
  original_reference_id: PMID:9256426
  review:
    summary: PMID:9256426 demonstrated in vitro refolding of mitochondrial malate dehydrogenase by purified HSP60/HSP10 in the presence of ATP.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:9256426
      supporting_text: In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
- term:
    id: GO:0042645
    label: mitochondrial nucleoid
  evidence_type: IDA
  original_reference_id: PMID:10869431
  review:
    summary: Crosslinking study showing HSP60 associates with mtDNA. Consistent with role in nucleoid structure.
    action: KEEP_AS_NON_CORE
    reason: Moonlighting function related to mtDNA maintenance.
- term:
    id: GO:0045041
    label: protein import into mitochondrial intermembrane space
  evidence_type: IMP
  original_reference_id: PMID:1347713
  review:
    summary: PMID:1347713 demonstrated that HSP60 antifolding activity couples protein import into the matrix with export to the intermembrane space. This is a downstream consequence of its chaperonin activity rather than a distinct function.
    action: KEEP_AS_NON_CORE
    reason: Secondary to core chaperonin folding activity.
    supported_by:
    - reference_id: PMID:1347713
      supporting_text: Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space.
    - reference_id: file:yeast/HSP60/HSP60-deep-research-falcon.md
      supporting_text: |-
        Yeast mitochondrial precursor proteins associate with Hsp60 as folding intermediates after import; ATP-dependent folding/release has been demonstrated in classical imported substrate experiments (e.g., Su9-DHFR) cited in major yeast chaperone reviews.
- term:
    id: GO:0050821
    label: protein stabilization
  evidence_type: IMP
  original_reference_id: PMID:1359644
  review:
    summary: PMID:1359644 showed HSP60 prevents thermal inactivation of DHFR in vivo and prevents aggregation in vitro. Protein stabilization is a consequence of its chaperonin activity during heat stress.
    action: KEEP_AS_NON_CORE
    reason: Consequence of chaperonin activity under stress, not a distinct core function.
    supported_by:
    - reference_id: PMID:1359644
      supporting_text: The Hsp60 was required to prevent the thermal inactivation in vivo of native dihydrofolate reductase (DHFR) imported into mitochondria.
- term:
    id: GO:0051087
    label: protein-folding chaperone binding
  evidence_type: IPI
  original_reference_id: PMID:9256426
  review:
    summary: PMID:9256426 directly measured HSP60-HSP10 binding with high affinity (Kd 0.9 nM). This interaction is central to the chaperonin folding mechanism.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:9256426
      supporting_text: In the presence of ADP, one molecule of hsp10 binds to hsp60 with an apparent Kd of 0.9 nM and a second molecule of hsp10 binds with a Kd of 24 nM.
- term:
    id: GO:0051131
    label: chaperone-mediated protein complex assembly
  evidence_type: IMP
  original_reference_id: PMID:2645524
  review:
    summary: PMID:2645524 demonstrated that HSP60 is essential for assembly of imported proteins into oligomeric complexes. This is a key aspect of its chaperonin function.
    action: ACCEPT
    supported_by:
    - reference_id: PMID:2645524
      supporting_text: A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix.
- term:
    id: GO:0051604
    label: protein maturation
  evidence_type: IMP
  original_reference_id: PMID:8097278
  review:
    summary: PMID:8097278 studied loss of HSP60 function effects on matrix-targeted and intermembrane-targeted proteins, showing HSP60 is needed for proper maturation. This is a downstream consequence of its folding activity.
    action: KEEP_AS_NON_CORE
    reason: Protein maturation is a downstream consequence of chaperonin-assisted folding.
- term:
    id: GO:0005743
    label: mitochondrial inner membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1252253
  review:
    summary: Reactome annotation based on TIM23 PAM complex translocation pathway. HSP60 participates in this process but is primarily a matrix protein.
    action: KEEP_AS_NON_CORE
    reason: Association with inner membrane during protein import; primary location is matrix.
- term:
    id: GO:0005743
    label: mitochondrial inner membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1268014
  review:
    summary: Reactome annotation for precursor protein entry into TIM23 PAM complex. Same rationale as above.
    action: KEEP_AS_NON_CORE
    reason: Association with inner membrane during protein import.
- term:
    id: GO:0005743
    label: mitochondrial inner membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1268017
  review:
    summary: Reactome annotation for MPP presequence hydrolysis. Same rationale.
    action: KEEP_AS_NON_CORE
    reason: Association with inner membrane during protein import.
- term:
    id: GO:0005758
    label: mitochondrial intermembrane space
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1252255
  review:
    summary: Reactome annotation suggesting HSP60 is in the intermembrane space during the TOM40/TOM70 translocation process. HSP60 is not a resident IMS protein; it participates in protein import that transits the IMS.
    action: REMOVE
    reason: HSP60 is not a resident IMS protein. This annotation reflects its transient role in the import pathway.
- term:
    id: GO:0005758
    label: mitochondrial intermembrane space
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1268014
  review:
    summary: Same rationale as above. HSP60 is a matrix protein, not an IMS resident.
    action: REMOVE
    reason: HSP60 is not a resident IMS protein.
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1252253
  review:
    summary: Reactome annotation consistent with known matrix localization.
    action: ACCEPT
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-SCE-1252255
  review:
    summary: Reactome annotation. HSP60 is synthesized in the cytosol but is rapidly imported into mitochondria. The cytosol is not where HSP60 functions.
    action: REMOVE
    reason: HSP60 functions in the mitochondrial matrix, not the cytosol. Cytosolic presence is only transient during import.
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:0000043
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
  findings: []
- id: GO_REF:0000117
  title: Electronic Gene Ontology annotations created by ARBA machine learning models
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:10869431
  title: "In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins."
  findings:
  - statement: HSP60 crosslinks to mtDNA and binds replication origins and ssDNA
    supporting_text: "In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins."
- id: PMID:11502169
  title: Yeast mitochondrial dehydrogenases are associated in a supramolecular complex.
  findings:
  - statement: HSP60 identified in mitochondria by protein sequencing
    supporting_text: Yeast mitochondrial dehydrogenases are associated in a supramolecular complex.
- id: PMID:11805837
  title: Systematic identification of protein complexes in Saccharomyces cerevisiae by mass spectrometry.
  findings: []
- id: PMID:1347713
  title: Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space.
  findings:
  - statement: HSP60 couples import to IMS with its antifolding activity
    supporting_text: Antifolding activity of hsp60 couples protein import into the mitochondrial matrix with export to the intermembrane space.
- id: PMID:1359644
  title: Prevention of protein denaturation under heat stress by the chaperonin Hsp60.
  findings:
  - statement: HSP60 forms complexes with polypeptides under heat stress and mediates ATP-dependent refolding
    supporting_text: Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.
  - statement: HSP60 prevents thermal inactivation of imported DHFR in vivo
    supporting_text: The Hsp60 was required to prevent the thermal inactivation in vivo of native dihydrofolate reductase (DHFR) imported into mitochondria.
- id: PMID:14576278
  title: The proteome of Saccharomyces cerevisiae mitochondria.
  findings: []
- id: PMID:14597775
  title: A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae.
  findings:
  - statement: HSP60 functions in mtDNA nucleoid structure and transmission
    supporting_text: A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae.
- id: PMID:16429126
  title: Proteome survey reveals modularity of the yeast cell machinery.
  findings: []
- id: PMID:16554755
  title: Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.
  findings: []
- id: PMID:16823961
  title: "Toward the complete yeast mitochondrial proteome: multidimensional separation techniques for mitochondrial proteomics."
  findings: []
- id: PMID:19536198
  title: "An atlas of chaperone-protein interactions in Saccharomyces cerevisiae: implications to protein folding pathways in the cell."
  findings: []
- id: PMID:1978929
  title: The mitochondrial chaperonin hsp60 is required for its own assembly.
  findings:
  - statement: HSP60 requires pre-existing functional complex for self-assembly
    supporting_text: Functional pre-existing hsp60 complex is required in order to form new, assembled, 14-mer.
- id: PMID:24769239
  title: Quantitative variations of the mitochondrial proteome and phosphoproteome during fermentative and respiratory growth in Saccharomyces cerevisiae.
  findings: []
- id: PMID:2645524
  title: Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria.
  findings:
  - statement: HSP60 is essential for assembly of imported mitochondrial proteins
    supporting_text: A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix.
- id: PMID:37968396
  title: The social and structural architecture of the yeast protein interactome.
  findings: []
- id: PMID:7902576
  title: Identification and functional analysis of chaperonin 10, the groES homolog from yeast mitochondria.
  findings:
  - statement: Yeast cpn60 has ATPase activity; cpn10 required for cpn60-mediated refolding of Rubisco
    supporting_text: When dimeric ribulose-1,5-bisphosphate carboxylase (Rubisco) is denatured and allowed to bind to yeast cpn60, subsequent refolding of Rubisco is strictly dependent upon yeast cpn10.
- id: PMID:8097278
  title: "Loss of mitochondrial hsp60 function: nonequivalent effects on matrix-targeted and intermembrane-targeted proteins."
  findings:
  - statement: Loss of HSP60 function has different effects on matrix vs IMS proteins
    supporting_text: "Loss of mitochondrial hsp60 function: nonequivalent effects on matrix-targeted and intermembrane-targeted proteins."
- id: PMID:9256426
  title: Significance of chaperonin 10-mediated inhibition of ATP hydrolysis by chaperonin 60.
  findings:
  - statement: HSP10 binds HSP60 with Kd 0.9 nM in ADP
    supporting_text: In the presence of ADP, one molecule of hsp10 binds to hsp60 with an apparent Kd of 0.9 nM and a second molecule of hsp10 binds with a Kd of 24 nM.
  - statement: HSP60/HSP10 mediates ATP-dependent refolding of malate dehydrogenase
    supporting_text: In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
  - statement: HSP10 inhibits HSP60 ATPase by 40%, which is coupled to folding
    supporting_text: Hsp10 inhibits the ATPase activity of hsp60 by about 40%.
- id: Reactome:R-SCE-1252253
  title: TIM23 PAM complex translocates proteins from the mitochondrial intermembrane space to the mitochondrial matrix
  findings: []
- id: Reactome:R-SCE-1252255
  title: TOM40:TOM70 complex translocates proteins from the cytosol to the mitochondrial intermembrane space
  findings: []
- id: Reactome:R-SCE-1268014
  title: Precursor proteins enter TIM23 PAM complex
  findings: []
- id: Reactome:R-SCE-1268017
  title: MPP hydrolyzes presequence of matrix precursors
  findings: []
- id: file:yeast/HSP60/HSP60-deep-research-falcon.md
  title: Falcon deep research report on yeast HSP60 (P19882 / YLR259C)
  findings:
  - statement: |
      The primary molecular function of yeast Hsp60 is as an ATP-dependent protein
      folding chaperonin for mitochondrial matrix proteins, especially those imported
      as unfolded precursors; it does not perform a small-molecule chemical reaction
      but catalyzes conformational maturation of polypeptides.
    reference_section_type: RESULTS
    supporting_text: |-
      ATP-dependent **protein folding chaperonin** for mitochondrial matrix proteins, particularly those imported into mitochondria as unfolded precursors. (verghese2012biologyofthe pages 29-30, cabiscol2002mitochondrialhsp60resistance pages 1-1)
  - statement: |
      Hsp60 catalyzes conformational maturation of polypeptides by providing a protected
      folding environment and coordinating substrate binding/release with ATP hydrolysis
      and Hsp10 capping, rather than transforming a small-molecule substrate.
    reference_section_type: RESULTS
    supporting_text: |-
      Hsp60 does not catalyze a chemical transformation of a small molecule substrate; rather, it catalyzes **conformational maturation of polypeptides** by providing a protected folding environment and coordinating binding/release with ATP hydrolysis and Hsp10 capping.
  - statement: |
      In yeast Hsp60 forms a 14-subunit double ring (two heptameric rings) enclosing a
      cavity that accommodates clients up to ~50 kDa; imported precursors transiently
      associate as incompletely folded intermediates before ATP-dependent folding/release.
    reference_section_type: RESULTS
    supporting_text: |-
      In yeast specifically, Hsp60 forms a **14-subunit double-ring (two heptameric rings)**, creating a cavity that can accommodate client proteins up to ~**50 kDa**, and imported precursor proteins transiently associate with Hsp60 as incompletely folded intermediates before ATP-dependent folding/release.
  - statement: |
      The co-chaperonin Hsp10 (GroES-like) caps the folding cavity as a lid to create an
      encapsulated folding environment, and ATP hydrolysis plus nucleotide exchange govern
      substrate release and cycle reset.
    reference_section_type: RESULTS
    supporting_text: |-
      the co-chaperonin **Hsp10 (GroES-like)** caps the cavity (“lid”), enabling an encapsulated folding environment; ATP hydrolysis and nucleotide exchange govern release/reset.
  - statement: |
      Yeast Hsp60 is synthesized as a mitochondrial precursor with an N-terminal
      matrix-targeting presequence that is cleaved by the mitochondrial processing
      peptidase (MPP) after residue 21, yielding the mature matrix protein.
    reference_section_type: RESULTS
    supporting_text: |-
      Yeast Hsp60 is produced as a **mitochondrial precursor** with an N-terminal matrix-targeting presequence, cleaved by MPP after residue 21, consistent with mitochondrial import and processing to a mature matrix protein.
  - statement: |
      HSP60 is essential for viability; deletion/null mutants are inviable due to severe
      mitochondrial folding defects.
    reference_section_type: RESULTS
    supporting_text: |-
      HSP60 is **essential for viability**: deletion/null mutants are inviable due to severe mitochondrial folding defects.
  - statement: |
      Representative Hsp60-dependent yeast clients include F1-ATPase subunits, cytochrome
      b2, and the Rieske Fe-S protein; conditional Hsp60 mutants accumulate insoluble
      matrix aggregates.
    reference_section_type: RESULTS
    supporting_text: |-
      Representative mitochondrial proteins discussed as Hsp60-dependent/affected in yeast reviews include **F1-ATPase subunits**, **cytochrome b2**, and the **Rieske Fe–S protein**; conditional mutants can accumulate **insoluble matrix aggregates**.
  - statement: |
      The temperature-sensitive mif4 allele (Gly298Asp) causes the ~840 kDa Hsp60 complex
      to become insoluble within ~2 hours after temperature shift.
    reference_section_type: RESULTS
    supporting_text: |-
      A temperature-sensitive **mif4** allele (Gly298→Asp) has been reported to cause the existing ~**840 kDa** Hsp60 complex to become insoluble within ~2 hours after temperature shift, pelleting at 15,000×g; this phenotype is described in a chaperonin chronologue review synthesizing genetic/biochemical evidence.
  - statement: |
      Hsp60 is induced 2-3 fold at 42 degrees C and protects Fe/S enzymes from oxidative
      inactivation in a dose-dependent manner; reduced Hsp60 increases the labile iron
      pool, and iron chelation partially rescues survival and oxidation phenotypes,
      linking Hsp60 to oxidative-stress defense.
    reference_section_type: RESULTS
    supporting_text: |-
      The same work reports Hsp60 is induced **2–3× at 42°C** and that protection of Fe/S enzymes from oxidative inactivation is **dose-dependent** on Hsp60 levels; reduced Hsp60 increased the labile iron pool (calcein assay), and iron chelation (deferoxamine) partially rescued survival and oxidation phenotypes.
  - statement: |
      A reported extra-mitochondrial pool of HSP60 (~15-20% cytoplasmic, ~80-85%
      mitochondrial) is explicitly noted as not yeast-specific, so it does not support a
      cytoplasmic localization annotation for yeast Hsp60.
    reference_section_type: RESULTS
    supporting_text: |-
      In broader eukaryotic contexts, HSP60 is predominantly mitochondrial and can also be detected in extra-mitochondrial compartments; one 2024 review summarizes a distribution of ~**80–85% mitochondrial** and ~**15–20% cytoplasmic** for HSP60 (not yeast-specific).
core_functions:
- description: >-
    Mitochondrial group I chaperonin (GroEL homolog) that forms a tetradecameric
    double-ring complex. Uses ATP hydrolysis to drive the folding of newly imported
    and heat-denatured proteins within its central cavity. Cooperates with the
    co-chaperonin HSP10 (GroES homolog), which caps the folding chamber and
    modulates ATPase activity. Essential for mitochondrial biogenesis and protein
    homeostasis.
  molecular_function:
    id: GO:0140662
    label: ATP-dependent protein folding chaperone
  directly_involved_in:
  - id: GO:0006457
    label: protein folding
  - id: GO:0042026
    label: protein refolding
  - id: GO:0051131
    label: chaperone-mediated protein complex assembly
  locations:
  - id: GO:0005759
    label: mitochondrial matrix
  supported_by:
  - reference_id: PMID:9256426
    supporting_text: In the presence of ATP, the purified yeast chaperonins mediate the refolding of mitochondrial malate dehydrogenase.
  - reference_id: PMID:2645524
    supporting_text: A nuclear encoded mitochondrial heat-shock protein hsp60 is required for the assembly into oligomeric complexes of proteins imported into the mitochondrial matrix.
  - reference_id: PMID:1359644
    supporting_text: Hsp60 bound to DHFR in the course of thermal denaturation, preventing its aggregation, and mediated its adenosine triphosphate-dependent refolding at increased temperatures.

HSP60

Gene Description

Existing Annotations Review

Core Functions

References

Deep Research

Falcon

Research Report: Saccharomyces cerevisiae HSP60 (UniProt P19882; ORF YLR259C)

0) Target verification (mandatory)

1) Key concepts and definitions (current understanding)

1.1 What Hsp60 is

1.2 Core mechanism: ATP-driven folding in an encapsulated cavity

1.3 Cellular role in mitochondrial protein biogenesis and proteostasis

2) Functional annotation for yeast HSP60 (what it does)

2.1 Primary molecular function

2.2 Subcellular localization and targeting

3) Biological processes, pathways, and key client proteins

3.1 Mitochondrial protein import and folding pathway

3.2 Essentiality and representative clients

4) Phenotypes and experimental evidence (selected high-confidence examples)

4.1 Temperature-sensitive mif4 allele and complex behavior

4.2 Oxidative stress defense via protection of Fe/S proteins (quantitative)

5) Recent developments (prioritizing 2023–2024)

5.1 2023: New rules for mitochondrial targeting sequences (Hsp60 used as a prototypical precursor)

5.2 2023: Environmental/toxicology application—HSP60 as a stress-response readout

5.3 2024: Updated synthesis of HSP60 mechanism and regulation (contextual, not yeast-specific)

6) Current applications and real-world implementations

7) Expert opinions and synthesis (authoritative interpretation)

8) Relevant statistics and quantitative data (from included studies)

9) Visual evidence (tables/figures)

Evidence map (summary table)

10) Key source list with URLs and publication dates (most relevant)

Artifacts

Citations

📚 Additional Documentation

Bioreason Rl Predictions

BioReason Chat Export

Thinking Trace

Functional Summary

UniProt Summary

InterPro Domains

GO Terms

Bioreason Rl Review

BioReason-Pro RL Review: HSP60 (S. cerevisiae)

Functional Summary Review

Notes on thinking trace

📄 View Raw YAML