nuclear pore inner ring

GO:0044611 · Other · Multiprotein complex · Proposed

A ring-shaped eukaryotic nuclear pore subcomplex built from inner-ring scaffold nucleoporins around the central transport channel. [GO:0044611]

Synonyms: inner ring complex

Part of: nuclear pore (GO:0005643)

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
Nup192/Nup205-family nucleoporin	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NUP192	UNKNOWN	Large scaffold nucleoporin family represented in the Saccharomyces cerevisiae nuclear pore inner-ring scaffold. `DOI:10.1016/j.cell.2011.06.039` Amlacher et al. 2011 used a thermophilic fungus to study conserved nucleoporins and nuclear-pore assembly. `DOI:10.1038/s41422-022-00632-y` Li et al. 2022 resolved Nup192, Nup188, Nup170, and Nup157 in the near-atomic Saccharomyces inner ring.
Nup188-family nucleoporin	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NUP188	UNKNOWN	Large scaffold nucleoporin family represented in the Saccharomyces cerevisiae nuclear pore inner-ring scaffold. `DOI:10.1016/j.cell.2011.06.039` Amlacher et al. 2011 used a thermophilic fungus to study conserved nucleoporins and nuclear-pore assembly. `DOI:10.1038/s41422-022-00632-y` Li et al. 2022 resolved Nup192, Nup188, Nup170, and Nup157 in the near-atomic Saccharomyces inner ring.
Nup170/Nup155-family nucleoporin	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NUP170	UNKNOWN	Large scaffold nucleoporin family represented in the Saccharomyces cerevisiae nuclear pore inner-ring scaffold. `DOI:10.1016/j.cell.2011.06.039` Amlacher et al. 2011 used a thermophilic fungus to study conserved nucleoporins and nuclear-pore assembly. `DOI:10.1038/s41422-022-00632-y` Li et al. 2022 resolved Nup192, Nup188, Nup170, and Nup157 in the near-atomic Saccharomyces inner ring.
Nup157-family nucleoporin	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NUP157	UNKNOWN	Large scaffold nucleoporin family represented in the Saccharomyces cerevisiae nuclear pore inner-ring scaffold. `DOI:10.1016/j.cell.2011.06.039` Amlacher et al. 2011 used a thermophilic fungus to study conserved nucleoporins and nuclear-pore assembly. `DOI:10.1038/s41422-022-00632-y` Li et al. 2022 resolved Nup192, Nup188, Nup170, and Nup157 in the near-atomic Saccharomyces inner ring.

Taxonomic distribution

NCBITaxon:2759 Eukaryota — COMMON: Inner-ring scaffold nucleoporins are a conserved architectural layer of eukaryotic nuclear pores, with fungal and metazoan pores using related but not identical Nup paralog sets. [DOI:10.1146/annurev-biophys-052118-115308]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model in which the near-atomic structure of the nuclear pore inner ring was resolved. [DOI:10.1038/s41422-022-00632-y]

Functions

nuclear-pore inner scaffold — The nuclear pore inner ring contributes the inner scaffold around the central transport channel.
- DOI:10.1126/science.aac9176 Stuwe et al. 2015 determined a fungal inner-ring architecture that placed scaffold nucleoporins around the transport channel.
- DOI:10.1016/j.cell.2021.12.015 Akey et al. 2022 resolved how the inner-ring scaffold fits within the yeast nuclear pore.

Mechanism graphs

Large scaffold Nups build the inner ring (ASSEMBLY)

Large Saccharomyces scaffold nucleoporin families occupy the nuclear pore inner ring around the central transport channel.

Subject	Predicate	Object	Evidence
Nup192/Nup205-family nucleoporin	contributes to	nuclear pore inner ring	`DOI:10.1038/s41422-022-00632-y` Li et al. 2022 produced a near-atomic model of the Saccharomyces nuclear pore inner ring containing Nup192, Nup188, Nup170, and Nup157.
Nup188-family nucleoporin	contributes to	nuclear pore inner ring	`DOI:10.1038/s41422-022-00632-y` Li et al. 2022 produced a near-atomic model of the Saccharomyces nuclear pore inner ring containing Nup192, Nup188, Nup170, and Nup157.
Nup170/Nup155-family nucleoporin	contributes to	nuclear pore inner ring	`DOI:10.1038/s41422-022-00632-y` Li et al. 2022 produced a near-atomic model of the Saccharomyces nuclear pore inner ring containing Nup192, Nup188, Nup170, and Nup157.
Nup157-family nucleoporin	contributes to	nuclear pore inner ring	`DOI:10.1038/s41422-022-00632-y` Li et al. 2022 produced a near-atomic model of the Saccharomyces nuclear pore inner ring containing Nup192, Nup188, Nup170, and Nup157.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral protein-family groundings for large inner-ring nucleoporin classes. The first inner-ring record leaves these Nup classes reviewed-label only because inner-ring paralogs and ortholog names vary between budding yeast, other fungi, and metazoans; exact InterPro, Pfam, or NCBIfam accessions should be resolved family-by-family.
CURATION_TODO (OPEN): Resolve whether linker nucleoporins and the central-channel nucleoporin complex should be modeled as components of the nuclear pore inner ring or left to neighboring NPC records. The first inner-ring record intentionally models only the large Saccharomyces scaffold Nups. Li et al. 2022 also place Nic96 and the Nup57/Nup49/Nsp1 central-channel complex in the near-atomic inner-ring model, so those linker and FG Nups need a separate boundary pass before they are added or explicitly assigned to adjacent nuclear-pore records.

Evidence

GO:0044611 Gene Ontology cellular-component term for the nuclear pore inner ring.
GO:0005643 Gene Ontology cellular-component term for the nuclear pore.
DOI:10.1016/j.cell.2011.06.039 Amlacher et al. 2011, 'Insight into Structure and Assembly of the Nuclear Pore Complex by Utilizing the Genome of a Eukaryotic Thermophile', Cell.
DOI:10.1126/science.aac9176 Stuwe et al. 2015, 'Architecture of the fungal nuclear pore inner ring complex', Science.
DOI:10.1038/s41422-022-00632-y Li et al. 2022, 'Near-atomic structure of the inner ring of the Saccharomyces cerevisiae nuclear pore complex', Cell Research.
DOI:10.1016/j.cell.2021.12.015 Akey et al. 2022, 'Comprehensive structure and functional adaptations of the yeast nuclear pore complex', Cell.
DOI:10.1146/annurev-biophys-052118-115308 Hampoelz et al. 2019, 'Structure and Assembly of the Nuclear Pore Complex', Annual Review of Biophysics.

Curation history

2026-09-11T07:03:10Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-11T07:04:21Z codex · EXPANDED_RECORD — Added inner-ring-complex synonymy, nuclear-pore parthood, four large Nup scaffold component classes, Eukaryota distribution, a Saccharomyces cerevisiae example, nuclear-pore scaffold function, DOI/GO evidence, an inner-ring assembly graph, and a Nup grounding TODO.
2026-09-11T07:17:39Z codex · ADDRESSED_REVIEW — Resolved #434 and #435 by changing central-channel lining wording to around-channel scaffold wording and adding an open TODO for deferred Nic96, Nup53/Nup59, and CNT or FG-channel component-boundary curation.

Source: data/structures/other/nuclear_pore_inner_ring.yaml