dityrosine layer of spore wall

GO:0005630 · Spore · Envelope layer · Proposed

The outermost layer of the spore wall, as described in Saccharomyces. [GO:0005630]

Part of: ascospore wall (GO:0005619)

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

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
dityrosine-containing spore-wall macromolecule	Other	part of	Reviewed label only (reviewed name; no accession asserted)			ESSENTIAL	Dityrosine-bearing wall material that forms the outermost layer of the Saccharomyces ascospore wall. `DOI:10.1016/S0021-9258(18)77231-1` Briza et al. 1990 characterized a DL-dityrosine-containing macromolecule isolated from yeast ascospore walls. `DOI:10.1016/S0021-9258(17)35659-4` Briza et al. 1986 identified dityrosine as a prominent component of the yeast ascospore wall.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast builds a dityrosine-rich outermost layer during ascospore-wall maturation; no broader Saccharomycotina distribution is asserted in this standalone layer record. [DOI:10.1128/MMBR.69.4.565-584.2005]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model in which a DL-dityrosine-containing macromolecule was biochemically characterized from isolated ascospore walls. [DOI:10.1016/S0021-9258(18)77231-1]

Functions

outer ascospore-wall stress barrier — The dityrosine-containing outermost layer contributes to the mature Saccharomyces ascospore surface that resists adverse environmental conditions.
- DOI:10.1073/pnas.91.10.4524 Briza et al. 1994 describe dityrosine as a sporulation-specific yeast ascospore-wall component essential for spore resistance to adverse environmental conditions while defining DIT1/DIT2-dependent LL-dityrosine precursor synthesis.
- DOI:10.1128/MMBR.69.4.565-584.2005 Neiman 2005 reviews dityrosine as an outer spore-wall component needed for the resistant mature spore surface.

Mechanism graphs

Dityrosine-containing material caps the Saccharomyces ascospore wall (ASSEMBLY)

In Saccharomyces cerevisiae, dityrosine-containing macromolecular material builds the outermost ascospore-wall layer above the chitosan layer and contributes to the mature stress-resistant spore surface.

Subject	Predicate	Object	Evidence
dityrosine-containing spore-wall macromolecule	forms	dityrosine layer of spore wall	`DOI:10.1016/S0021-9258(18)77231-1` Briza et al. 1990 characterized a DL-dityrosine-containing macromolecule from yeast ascospore walls. `GO:0005630` GO:0005630 identifies the complete dityrosine layer as an outermost Saccharomyces spore-wall layer.
dityrosine layer of spore wall	overlies	chitosan layer of spore wall	`GO:0005630` GO:0005630 defines the dityrosine layer as the outermost Saccharomyces spore-wall layer. `GO:0005631` GO:0005631 defines the chitosan layer as the second outermost Saccharomyces spore-wall layer. `DOI:10.1371/journal.pgen.1003700` Lin et al. 2013 studied assembly of the Saccharomyces outer spore-wall layers.
dityrosine layer of spore wall	is outermost layer of	ascospore wall	`GO:0005630` GO:0005630 defines the dityrosine layer as part of the Saccharomyces spore wall. `GO:0005619` GO places GO:0005630 as part of the ascospore wall.
dityrosine layer of spore wall	contributes to	spore environmental stress resistance	`DOI:10.1073/pnas.91.10.4524` Briza et al. 1994 described dityrosine as a sporulation-specific yeast ascospore-wall component tied to spore resistance under adverse environmental conditions. `DOI:10.1128/MMBR.69.4.565-584.2005` Neiman 2005 reviews the dityrosine layer as part of the stress-resistant mature spore wall.

Discussions

CURATION_TODO (OPEN): Resolve an exact source-neutral grounding for the mature dityrosine-containing spore-wall macromolecule. The record has enough biochemical support to name the dityrosine-containing wall material, but the exact chemical boundary of the assembled insoluble wall macromolecule has not been matched to a source-neutral CHEBI identifier.
INTERPRETATION (RESOLVED): Treat Dit1 and Dit2 as precursor biosynthetic enzymes rather than dityrosine-layer constituents. DIT1 and DIT2 encode sporulation-specific enzymes that synthesize soluble LL-dityrosine-containing precursors before incorporation into the wall, so they support the precursor-biosynthesis pathway rather than a mature-layer constituent call.
INTERPRETATION (RESOLVED): Keep the Saccharomyces dityrosine layer separate from the Schizosaccharomyces Isp3 layer. GO:0005630 denotes the Saccharomyces dityrosine layer, whereas GO:1990916 denotes the Schizosaccharomyces pombe Isp3 spore-wall layer.

Evidence

GO:0005630 Gene Ontology cellular-component term for the Saccharomyces spore-wall dityrosine layer.
GO:0005619 Gene Ontology cellular-component term for the broader ascospore wall that contains the dityrosine layer.
GO:0005631 Gene Ontology cellular-component term for the chitosan layer below the outermost Saccharomyces dityrosine layer.
DOI:10.1016/S0021-9258(17)35659-4 Briza et al. 1986, Dityrosine Is a Prominent Component of the Yeast Ascospore Wall. A Proof of Its Structure, Journal of Biological Chemistry.
DOI:10.1016/S0021-9258(18)77231-1 Briza et al. 1990, Characterization of a DL-dityrosine-containing Macromolecule from Yeast Ascospore Walls, Journal of Biological Chemistry.
DOI:10.1073/pnas.91.10.4524 Briza et al. 1994, The Sporulation-Specific Enzymes Encoded by the DIT1 and DIT2 Genes Catalyze a Two-Step Reaction Leading to a Soluble LL-Dityrosine-Containing Precursor of the Yeast Spore Wall, Proceedings of the National Academy of Sciences.
DOI:10.1128/EC.3.6.1464-1475.2004 Coluccio et al. 2004, Morphogenetic Pathway of Spore Wall Assembly in Saccharomyces cerevisiae, Eukaryotic Cell.
DOI:10.1128/MMBR.69.4.565-584.2005 Neiman 2005, Ascospore Formation in the Yeast Saccharomyces cerevisiae, Microbiology and Molecular Biology Reviews.
DOI:10.1371/journal.pgen.1003700 Lin et al. 2013, A Highly Redundant Gene Network Controls Assembly of the Outer Spore Wall in S. cerevisiae, PLOS Genetics.

Curation history

2026-09-23T01:39:38Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-23T01:41:48Z codex · EXPANDED_RECORD — Added ascospore-wall parthood, a reviewed-label-only dityrosine-containing macromolecule component, Saccharomyces cerevisiae scope, a stress-barrier function, GO/DOI evidence, a nonmechanistic layer topology graph, and boundary discussions for macromolecule grounding and precursor enzymes.
2026-09-23T01:52:35Z codex · ADDRESS_REVIEW — Resolved PR #1342 review issue #1343 by tightening DOI:10.1073/pnas.91.10.4524 evidence notes so canonical-example and stress-resistance claims match the cited literature.

Source: data/structures/spore/dityrosine_layer_of_spore_wall.yaml