nucleolar peripheral inclusion body

GO:0140602 · Inclusion · Inclusion body · Proposed

An intranuclear inclusion at the nucleolar periphery in which nuclear factors collect reversibly during acute heat stress or starvation. [GO:0140602]

Figure 7. Severe-heat NuRs at 42 C for 15 minutes. Panel a compares the Rho1 reporter in fission yeast and budding-yeast W303/BY4741 derivatives. Panel b shows fission-yeast Mas5, Ssa2, Ssa1, Hsp104 and Guk1-9 reporter signals, including the mas5 deletion control. Insets enlarge nuclear rings; scale bars are 5 micrometers. Panel c is a proposed assembly/recovery model, not a separate measurement. W303 preparation includes 50-fold culture concentration. FLUORESCENCE · *Schizosaccharomyces pombe* (`NCBITaxon:4896`) · Susanna Boronat, Margarita Cabrera, Montserrat Vega, Jorge Alcalá, Silvia Salas-Pino, Rafael R. Daga, José Ayté, Elena Hidalgo; CC BY, via PubMed Central · CC_BY_4_0 · source: PMC PMC10342647.1 ijms-24-11202-f007 · `DOI:10.3390/ijms241311202`

Synonyms: nucleolar rings; NuRs

Part of: nucleus (GO:0005634)

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Essential	Role
heterogeneous nuclear protein cargo	Other	part of	Reviewed label only (reviewed name; no accession asserted)		UNKNOWN	Stress-sequestered material rather than a fixed complex. Heat-stressed fission yeast recruits Alm1, Nup211, Nup132, Pab2, Nab2 and several cell-cycle regulators, among other factors. Nup85 and Mex67 are resolved separately below. These proteins are not asserted to share a family or to be present under every inducing condition. `DOI:10.1016/j.celrep.2020.108377` Results and Figures 1-2 distinguish relocated proteins from unaffected NPC proteins and the central Gar2-positive domain.
Nucleoporin Nup85-like	Protein	part of	`InterPro:IPR011502`	nup85	UNKNOWN	Nup85 leaves the nuclear pore and accumulates in NuRs during acute heat stress in fission yeast. Its fluorescence recovery is reduced at NuRs; during recovery it returns to the nuclear periphery. `DOI:10.1016/j.celrep.2020.108377` Figures 1c and 3b-d show redistribution, reduced mobility and recovery. `InterPro:IPR011502` The exact reviewed Q9UUE5 protein has one integrated match, this family.
Nuclear RNA export factor	Protein	part of	`InterPro:IPR030217`	mex67	UNKNOWN	Mex67 accumulates in heat-induced NuRs and overlaps Alm1-marked rings in fission yeast. Its ordinary mRNA-export function does not imply that export is active at NuRs or that the complete export machinery is present. `DOI:10.1016/j.celrep.2020.108377` Figures 1e-g and 3c establish localization and reduced mobility. `InterPro:IPR030217` Native Q9Y8G3 integrated matches distinguish the family from repeat, domain and superfamily entries.
Heat shock protein 70 family	Protein	part of	`InterPro:IPR013126`	ssa1, ssa2	UNKNOWN	Ssa1 and Ssa2 are chaperone residents of severe-heat NuRs in fission yeast. This localization does not establish residence or essentiality for every Hsp70 paralogue. `DOI:10.3390/ijms241311202` Results 2.5 and Figure 7b image Ssa1-GFP and GFP-Ssa2 at NuRs after 15 minutes at 42 C. `InterPro:IPR013126` Both reviewed Ssa1 and Ssa2 have this family in their complete native integrated match sets.
DnaJ homolog subfamily A member 1/2-like	Protein	part of	`InterPro:IPR044713`	mas5	CONDITIONAL	Mas5 is a NuR-localized chaperone in fission yeast. Loss of Mas5 blocks the tested severe-heat reporter NuRs; this is an organism- and assay-specific requirement, not family-wide essentiality. `DOI:10.3390/ijms241311202` Results 2.5 and Figure 7a-b show Mas5 localization and loss-of-function effects. `InterPro:IPR044713` Native reviewed O74752 matches this family as well as the broader DnaJ family and several domains.
Hsp104-type disaggregase	Protein	acts on	Reviewed label only (reviewed name; no accession asserted)	hsp104	DISPENSABLE	NuR-associated disaggregase in fission yeast that supports timely clearance during recovery. NuRs still form in its absence. Delayed clearance and regrowth after deletion do not isolate a NuR-only survival mechanism. `DOI:10.1016/j.celrep.2020.108377` Figure 4d compares Nup85-marked NuRs in wild type and hsp104 deletion cells during heat stress and recovery. `DOI:10.3390/ijms241311202` Figure 7b directly images Hsp104-GFP at severe-heat NuRs.

Organism-specific protein examples

Named proteins in which each component's role was established, with the organism the evidence comes from. The component above is the taxon-agnostic family; these are the specific entries behind it.

Nucleoporin Nup85-like

Accession	Protein	Gene	Organism	Entry
`UniProtKB:Q9UUE5`	Nucleoporin nup85	nup85	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reviewed reference-sequence identity for the fission-yeast factor. Localization and role rely on the cited experiments, not on the protein name or a claim that all tagged strains have this exact genotype. `UniProtKB:Q9UUE5` Native reviewed entry verifies accession, gene, name and strain taxon. `DOI:10.1016/j.celrep.2020.108377` Figures 1c and 3b-d show redistribution, reduced mobility and recovery.

Nuclear RNA export factor

Accession	Protein	Gene	Organism	Entry
`UniProtKB:Q9Y8G3`	mRNA export factor mex67	mex67	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reviewed reference-sequence identity for the fission-yeast factor. Localization and role rely on the cited experiments, not on the protein name or a claim that all tagged strains have this exact genotype. `UniProtKB:Q9Y8G3` Native reviewed entry verifies accession, gene, name and strain taxon. `DOI:10.1016/j.celrep.2020.108377` Figures 1e-g and 3c establish localization and reduced mobility.

Heat shock protein 70 family

Accession	Protein	Gene	Organism	Entry
`UniProtKB:Q10265`	Probable heat shock protein ssa1	ssa1	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reviewed reference-sequence identity for the fission-yeast factor. Localization and role rely on the cited experiments, not on the protein name or a claim that all tagged strains have this exact genotype. `UniProtKB:Q10265` Native reviewed entry verifies accession, gene, name and strain taxon. `DOI:10.3390/ijms241311202` Results 2.5 and Figure 7b image Ssa1-GFP and GFP-Ssa2 at NuRs after 15 minutes at 42 C.
`UniProtKB:O59855`	Probable heat shock protein ssa2	ssa2	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reviewed reference-sequence identity for the fission-yeast factor. Localization and role rely on the cited experiments, not on the protein name or a claim that all tagged strains have this exact genotype. `UniProtKB:O59855` Native reviewed entry verifies accession, gene, name and strain taxon. `DOI:10.3390/ijms241311202` Results 2.5 and Figure 7b image Ssa1-GFP and GFP-Ssa2 at NuRs after 15 minutes at 42 C.

DnaJ homolog subfamily A member 1/2-like

Accession	Protein	Gene	Organism	Entry
`UniProtKB:O74752`	Mitochondrial protein import protein mas5	mas5	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reviewed reference-sequence identity for the fission-yeast factor. Localization and role rely on the cited experiments, not on the protein name or a claim that all tagged strains have this exact genotype. `UniProtKB:O74752` Native reviewed entry verifies accession, gene, name and strain taxon. `DOI:10.3390/ijms241311202` Results 2.5 and Figure 7a-b show Mas5 localization and loss-of-function effects.

Hsp104-type disaggregase

Accession	Protein	Gene	Organism	Entry
`UniProtKB:O94641`	Heat shock protein 104	hsp104	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reviewed reference-sequence identity for the fission-yeast factor. Localization and role rely on the cited experiments, not on the protein name or a claim that all tagged strains have this exact genotype. `UniProtKB:O94641` Native reviewed entry verifies accession, gene, name and strain taxon. `DOI:10.1016/j.celrep.2020.108377` Figure 4d compares Nup85-marked NuRs in wild type and hsp104 deletion cells during heat stress and recovery.

Canonical examples

NCBITaxon:4896 Schizosaccharomyces pombe — Defining acute-heat experiments shift cells from 25 C to 42 C for 10 or 20 minutes, followed where specified by recovery at 25 C. [DOI:10.1016/j.celrep.2020.108377]
NCBITaxon:4932 Saccharomyces cerevisiae — Figure 7a reports NuRs in W303 and BY4741 derivatives at 42 C for 15 minutes. Methods 4.3 requires 50-fold concentration of W303 cultures before heat treatment; that preparation is not generalized to BY4741 or fission yeast. [DOI:10.3390/ijms241311202]
NCBITaxon:284812 Schizosaccharomyces pombe 972h- — Native NCBI strain taxon for the reviewed reference-sequence examples. This does not assign every tagged or mutant strain in the papers to an independently verified genotype. [UniProtKB:Q9UUE5]

Functions

reversible sequestration of nuclear proteins — Collects selected nuclear factors during acute heat stress. Nup85 and Mex67 show reduced mobility; recovery releases factors to their usual locations. Coordinated shutdown of nuclear activities and protection from damage are interpretations, not a proven NuR-specific causal pathway.
- DOI:10.1016/j.celrep.2020.108377 Figures 1-3 and Discussion support sequestration and release while distinguishing the proposed physiological model.

Mechanism graphs

NuR formation under acute heat stress (ASSEMBLY)

Subject	Predicate	Object	Evidence
Acute 42 C heat stress	induces	nucleolar peripheral inclusion body	`DOI:10.1016/j.celrep.2020.108377` Figures 1 and 3a-b.
mas5 deletion	blocks	nucleolar peripheral inclusion body	`DOI:10.3390/ijms241311202` Results 2.5 and Figure 7a-b.
37 C preconditioning for 45 minutes before 42 C stress	suppresses	nucleolar peripheral inclusion body	`DOI:10.1016/j.celrep.2020.108377` Results on thermotolerance report reduced NuR recruitment; supplemental panels were not independently inspected.

NuR clearance after acute heat stress (DISASSEMBLY)

Subject	Predicate	Object	Evidence
Return to 25 C after acute heat stress	permits	NuR disassembly during recovery	`DOI:10.1016/j.celrep.2020.108377` Figure 3d.
hsp104 deletion	delays	NuR disassembly during recovery	`DOI:10.1016/j.celrep.2020.108377` Figure 4d.
Repressed purg1-driven hsf1 expression	delays	NuR disassembly during recovery	`DOI:10.1016/j.celrep.2020.108377` Figure 4c and Results; this is not a direct physical interaction.

Discussions

INTERPRETATION (RESOLVED): Keep NuRs distinct from neighboring deposits and similarly abbreviated assemblies. Spatial similarity and a shared stress response are not exact structure identity.
INTERPRETATION (RESOLVED): Separate sequestered cargo from intact complexes, central nucleolar markers and upstream regulators. Protein redistribution and perturbation phenotypes do not establish whole-complex membership.
CURATION_TODO (OPEN): Extend the component inventory and resolve exact Hsp104 and heterogeneous-cargo groundings where possible. The six-class core is not an exhaustive native composition or a fixed stoichiometry.
INTERPRETATION (OPEN): Determine which composition and clearance mechanisms are shared between heat-induced and starvation-associated inclusions. GO groups inducing conditions, but this does not make experimental mechanisms interchangeable.
CURATION_TODO (OPEN): Resolve broader distribution, native-client datasets and physical properties with structure-specific evidence. Two yeast models do not establish fungal prevalence or universal condensate physics.

Evidence

GO:0140602 Active cellular-component identity and exact synonyms verified through native QuickGO. The definition cites PMID 33176152 and PMID 37128864 and includes both heat stress and starvation.
GO:0042405 QuickGO directly lists GO:0140602 as an is_a child of nuclear inclusion body; nucleus lists nuclear inclusion body as part_of.
DOI:10.1016/j.celrep.2020.108377 Gallardo et al. (2020), PMID 33176152. Full publisher-version PDF read from the Universidad Pablo de Olavide repository, https://hdl.handle.net/10433/22772. Main Results, Discussion, Methods and captions inspected; Figures 1-2 visually inspected. Supplemental materials and raw data were not independently inspected. CC BY-NC-ND 4.0 figures are not hosted.
DOI:10.3390/ijms241311202 Boronat et al. (2023), PMID 37446379, PMC10342647.1. Native JATS Results 2.5, Discussion, Methods and Figure 7 caption read; figure pixels inspected. Native metadata confirms non-retracted CC BY 4.0 article. Supplemental panels were not independently inspected.
DOI:10.1242/jcs.260727 Hiraoka et al. (2023), PMID 37128864. Publisher Results around Figure 3 and Discussion read: Cdc2, Cdc13 and Clp1 accumulate peripherally during stationary phase or glucose depletion, distinct from central Gar1/Gar2. This supports GO's broader scope, not identical heat-stress composition or mechanism.

Curation history

2026-10-05T11:39:49Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-05T11:41:52Z codex · EXPANDED_RECORD — Added exact GO identity and hierarchy, six bounded component classes and six reference proteins, two intervention graphs, source-scope discussions and an inspected CC BY 4.0 figure.
2026-10-05T11:57:56Z codex · RESOLVED_REVIEW — Resolved issue #2063 by limiting the fission-yeast canonical-example note to the experiment supported by its own 2020 reference; independently cited 2023 assay descriptions remain elsewhere.

Source: data/structures/inclusion/nucleolar_peripheral_inclusion_body.yaml