actin body

GO:0099079 · Cytoskeleton · Other · Proposed

An amorphous cytoplasmic assembly of actin filaments and selected actin-binding proteins in growth-arrested yeast cells, distinct from cortical actin patches and actin cables. [GO:0099079]

Figure 5 supplement 1. Panel A shows phalloidin-stained actin bodies in prototrophic Saccharomyces cerevisiae rho-zero cells after 24 hours in YPD, overlaid with DIC. Panel B instead reports Scl1-GFP proteasome localization after six days; its green puncta are not actin-body staining. Scale bars are 2 micrometers. Panel C compares cell volumes after seven days and does not measure actin-body dimensions. FLUORESCENCE · *Saccharomyces cerevisiae* (`NCBITaxon:4932`) · Damien Laporte, Laëtitia Gouleme, Laure Jimenez, Ines Khemiri, Isabelle Sagot; CC BY, via PubMed Central · CC_BY_4_0 · source: PMC PMC6177259.1 fig5s1 · `DOI:10.7554/eLife.35685`

Part of: GO:0015629 — actin cytoskeleton (no local record); GO:0005737 — cytoplasm (no local record)

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
Actin family	Protein	part of	`InterPro:IPR004000`	ACT1, ARP2	UNKNOWN	Act1 supplies the filament scaffold. The related Arp2 protein is only a partial colocalizer; shared family identity does not make Arp2 a substitute filament monomer. `DOI:10.1091/mbc.E06-04-0282` Figures 1-2 establish actin-rich bodies; the component-localization Results distinguish partial Arp2 colocalization.
Abp1-like actin-binding adaptor	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	ABP1	UNKNOWN	Budding-yeast Abp1 colocalizes with bodies and serves as a live-cell reporter. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast. `DOI:10.7554/eLife.35685` Figure 5 tracks Abp1-3xGFP bodies and subsequent individual-cell budding.
Abp140-like actin-binding methyltransferase	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	ABP140	UNKNOWN	Abp140 colocalizes with bodies; its methyltransferase annotation does not establish a catalytic requirement for body formation. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast.
Fimbrin/Plastin	Protein	part of	`InterPro:IPR039959`	SAC6, fim1	UNKNOWN	Fimbrin is a body-localized actin-bundling protein in both studied yeasts. The pleiotropic sac6 deletion phenotype does not establish family-wide body essentiality. `DOI:10.1091/mbc.E06-04-0282` Figure 3: Sac6 localization and pleiotropic deletion phenotype. `DOI:10.1083/jcb.201502025` Figure 6C: Fim1-GFP localizes to fission-yeast bodies during glucose-exhaustion-induced growth arrest.
F-actin-capping protein subunit alpha	Protein	part of	`InterPro:IPR002189`	CAP1	UNKNOWN	The budding-yeast alpha subunit colocalizes with bodies. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast.
F-actin-capping protein subunit beta	Protein	part of	`InterPro:IPR001698`	CAP2, acp2	UNKNOWN	The beta subunit localizes to bodies in budding and fission yeast. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast. `DOI:10.1083/jcb.201502025` Figure 6C: Acp2-GFP localizes to fission-yeast bodies during glucose-exhaustion-induced growth arrest.
Actin-related protein 2/3 complex subunit 5	Protein	part of	`InterPro:IPR006789`	ARC15	UNKNOWN	Partial budding-yeast body colocalizer; whole-complex membership and nucleation activity inside bodies are not established by this observation. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex.
Actin-related protein 2/3 complex subunit 3	Protein	part of	`InterPro:IPR007204`	ARC18	UNKNOWN	Partial budding-yeast body colocalizer, not a fixed stoichiometric constituent. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex.
Actin-related protein 2/3 complex subunit 2	Protein	part of	`InterPro:IPR007188`	ARC35	UNKNOWN	Partial budding-yeast body colocalizer, not evidence for all Arp2/3 subunits. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex.
Coronin	Protein	part of	`InterPro:IPR015505`	CRN1	UNKNOWN	Crn1 partially colocalizes in budding yeast. The fission-yeast study did not detect Crn1 in bodies, so membership is not generalized between these organisms. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `DOI:10.1083/jcb.201502025` The actin-body Results and Figure S5A report no Crn1 body localization under the tested condition.
Adenylate cyclase-associated CAP	Protein	part of	`InterPro:IPR001837`	SRV2	UNKNOWN	Srv2 partially colocalizes with budding-yeast bodies. It is distinct from the capping alpha subunit even though CAP1 is also a historical SRV2 alias. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex.

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.

Actin family

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P60010`	Actin	ACT1	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Figures 1-2: phalloidin staining and anti-actin immunogold identify F-actin-rich bodies. `https://www.uniprot.org/uniprotkb/P60010/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.
`UniProtKB:P32381`	Actin-related protein 2	ARP2	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `https://www.uniprot.org/uniprotkb/P32381/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Abp1-like actin-binding adaptor

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P15891`	Actin-binding protein	ABP1	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast. `https://www.uniprot.org/uniprotkb/P15891/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Abp140-like actin-binding methyltransferase

Accession	Protein	Gene	Organism	Entry
`UniProtKB:Q08641`	tRNA(Thr) (cytosine(32)-N(3))-methyltransferase	ABP140	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast. `https://www.uniprot.org/uniprotkb/Q08641/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Fimbrin/Plastin

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P32599`	Fimbrin	SAC6	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Figure 3E: Sac6-GFP colocalization; deletion also disrupts proliferating-cell actin. `https://www.uniprot.org/uniprotkb/P32599/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.
`UniProtKB:O59945`	Fimbrin	fim1	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1083/jcb.201502025` Figure 6C: Fim1-GFP localizes to fission-yeast bodies during glucose-exhaustion-induced growth arrest. `https://www.uniprot.org/uniprotkb/O59945/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

F-actin-capping protein subunit alpha

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P28495`	F-actin-capping protein subunit alpha	CAP1	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast. `https://www.uniprot.org/uniprotkb/P28495/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

F-actin-capping protein subunit beta

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P13517`	F-actin-capping protein subunit beta	CAP2	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Figure 3: GFP reporter colocalizes with phalloidin-stained actin bodies in stationary budding yeast. `https://www.uniprot.org/uniprotkb/P13517/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.
`UniProtKB:Q9HGP5`	F-actin-capping protein subunit beta	acp2	Schizosaccharomyces pombe 972h- (`NCBITaxon:284812`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1083/jcb.201502025` Figure 6C: Acp2-GFP localizes to fission-yeast bodies during glucose-exhaustion-induced growth arrest. `https://www.uniprot.org/uniprotkb/Q9HGP5/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Actin-related protein 2/3 complex subunit 5

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P40518`	Actin-related protein 2/3 complex subunit 5	ARC15	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `https://www.uniprot.org/uniprotkb/P40518/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Actin-related protein 2/3 complex subunit 3

Accession	Protein	Gene	Organism	Entry
`UniProtKB:Q05933`	Actin-related protein 2/3 complex subunit 3	ARC18	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `https://www.uniprot.org/uniprotkb/Q05933/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Actin-related protein 2/3 complex subunit 2

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P53731`	Actin-related protein 2/3 complex subunit 2	ARC35	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `https://www.uniprot.org/uniprotkb/P53731/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Coronin

Accession	Protein	Gene	Organism	Entry
`UniProtKB:Q06440`	Coronin-like protein	CRN1	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `https://www.uniprot.org/uniprotkb/Q06440/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Adenylate cyclase-associated CAP

Accession	Protein	Gene	Organism	Entry
`UniProtKB:P17555`	Adenylyl cyclase-associated protein	SRV2	Saccharomyces cerevisiae S288C (`NCBITaxon:559292`)	REVIEWED
Role and evidence (2 references) Reference-sequence exemplar for the species-level microscopy; the accession does not assert that the exact reference stock was imaged. `DOI:10.1091/mbc.E06-04-0282` Results, Actin Bodies Contain Specific Actin-binding Proteins: partial colocalization with bodies, not fixed occupancy or a complete Arp2/3 complex. `https://www.uniprot.org/uniprotkb/P17555/entry` Reviewed identity and gene verified live on 2026-10-05; localization is supported by the microscopy citation, not sequence annotation alone.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — VARIABLE: Demonstrated in growth-arrested laboratory cultures; frequency and association with subsequent proliferation depend on culture conditions and cell state. [DOI:10.7554/eLife.35685]
NCBITaxon:4896 Schizosaccharomyces pombe — VARIABLE: Bodies were observed after glucose-exhaustion-induced growth arrest. This does not assert constitutive presence or presence in every strain. [DOI:10.1083/jcb.201502025]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Single-cell tracking used BY4741/BY4742-related cultures grown seven days in YPD. The hosted Figure 5 supplement instead shows phalloidin-stained prototrophic rho-zero cells after 24 hours; these contexts are not conflated. [DOI:10.7554/eLife.35685]
NCBITaxon:4896 Schizosaccharomyces pombe — Figure 6C shows Fim1 and Acp2 localization and phalloidin-stained bodies after glucose exhaustion. The distinct quiescent microtubule bundle is not part of the actin body. [DOI:10.1083/jcb.201502025]

Mechanism graphs

Glucose metabolism enables actin-body mobilization (DISASSEMBLY)

Subject	Predicate	Object	Evidence
glucose uptake	provides substrate for	glucose catabolism	`DOI:10.1083/jcb.201009028` Figure 4B and the glucose-catabolism Results: uptake-defective and hexokinase-deficient mutants fail glucose-triggered mobilization.
glucose catabolism	enables	actin-body disassembly	`DOI:10.1083/jcb.201009028` Blocked glycolytic steps, glucose analogs and iodoacetate prevent mobilization. In pgi1 mutants fructose permits mobilization without ATP replenishment; water can raise ATP without mobilizing bodies.

Discussions

OPEN_QUESTION (OPEN): Does the actin body directly supply reusable actin to rebuilt patches and cables? Rapid refeeding-dependent disappearance and rebuilding without new protein synthesis support a reserve hypothesis, not traced transfer of body subunits. No established storage function or direct body-to-patch conversion is asserted.
CURATION_TODO (OPEN): Resolve exact source-neutral families for Abp1-like adaptors and Abp140-like actin-binding methyltransferases. Native InterPro matches were inspected completely; generic domains and the broader METTL2/6/8-like family do not precisely identify these components.
CURATION_TODO (OPEN): Resolve the gene and reporter called drebrin (Aap1) in the fission-yeast actin-body study. The paper reports a positive localizer, but native UniProt searches for aap1 return an amino-acid permease and an aspartyl aminopeptidase alias, not a verified drebrin. An app1 hit is not sufficient to correct the paper by inference. Supplementary strain and reporter provenance must establish the intended identity before an accession or a new family is assigned.
INTERPRETATION (RESOLVED): Do partial localizers establish a fixed actin-body composition? Membership strength differs between proteins and organisms; co-occurrence is not a stoichiometric reconstruction. Sac6 loss is pleiotropic. Scp1 perturbation does not establish Scp1 residence, and fission-yeast polarity proteins lost from cell tips are not thereby body constituents.
INTERPRETATION (RESOLVED): Does an actin body uniquely identify a viable quiescent cell? The 2018 study followed individual cells rather than inferring fate from a stationary population. Bodies occurred in cells with different subsequent proliferation outcomes.
KNOWLEDGE_GAP (OPEN): Which metabolic signal connects glycolysis to actin-body disassembly? Glucose-dependent mobilization requires metabolism, but ATP replenishment is neither necessary nor sufficient in the tested assays. This does not establish that basal ATP is dispensable or that pyruvate itself is the signal.

Evidence

GO:0099079 Exact nonobsolete cellular-component identity; native GO and cached OAK agree on actin-cytoskeleton parthood, not an is-a relation to the whole cytoskeleton.
GO:0110165 Native GO is-a parent: cellular anatomical structure.
GO:0015629 — actin cytoskeleton Actin cytoskeleton is a containing structure, not the record identity.
GO:0005737 — cytoplasm Cytoplasm denotes the cellular compartment containing the observed bodies.
DOI:10.1091/mbc.E06-04-0282 Sagot et al. 2006 defining study. Indexed primary Results and figure captions were readable; complete Methods were not recovered through the attempted XML/BioC/PDF routes. No verbatim snippets or figure bytes are taken from this source.
DOI:10.1083/jcb.201009028 Laporte et al. 2011, Metabolic status rather than cell cycle signals control quiescence entry and exit. Native primary Results and Methods support metabolic requirements for body mobilization, not complete proliferation on glucose alone.
DOI:10.1083/jcb.201502025 Laporte et al. 2015, A stable microtubule array drives fission yeast polarity reestablishment upon quiescence exit. Only the actin-body localization results are used here; microtubule-bundle functions remain outside this record.
DOI:10.7554/eLife.35685 Laporte et al. 2018, Mitochondria reorganization upon proliferation arrest predicts individual yeast cell fate. Direct cell tracking shows bodies in both quiescent and senescent subpopulations.

Curation history

2026-10-05T14:39:58Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-10-05T14:43:03Z codex · EXPANDED_RECORD — Added eleven component classes, fourteen verified protein examples, scoped yeast distribution, a two-edge disassembly mechanism, licensed microscopy and explicit family, reporter-identity and physiological-interpretation boundaries.
2026-10-05T14:44:18Z codex · CORRECTED_FIGURE_REFERENCES — Corrected two 2011 glucose-catabolism figure references from Figure 5 to Figure 4 after reading the native JATS captions.

Source: data/structures/cytoskeleton/actin_body.yaml