mating projection

GO:0005937 · Appendage · Appendage · Proposed

The projection formed by unicellular fungi in response to mating pheromone. [GO:0005937]

Synonyms: shmoo; conjugation tube

Has part: mating projection membrane (GO:0070250); mating projection tip (GO:0043332); mating projection base (GO:0001400); mating projection septin ring (GO:0032175); mating projection septin band (GO:0032162)

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

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — VARIABLE: Haploid budding-yeast cells extend mating projections after pheromone exposure rather than during every growth state. [DOI:10.1091/mbc.3.4.429]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model in which pheromone treatment induces a polarized mating projection containing Spa2-positive tips. [DOI:10.1091/mbc.3.4.429]

Functions

mating-projection polarized growth — The mating projection concentrates polarized-growth machinery at its tip to build a pheromone-induced fungal outgrowth.
- GO:0005937 GO:0005937 defines the projection as the structure formed by unicellular fungi in response to mating pheromone.
- DOI:10.1091/mbc.3.4.429 Read et al. 1992 used actin and beta-tubulin mutants to analyze Saccharomyces cerevisiae mating-projection formation.
- DOI:10.1083/jcb.200307065 Bidlingmaier and Snyder 2004 studied polarisome components during cyclic initiation and termination of yeast mating-projection growth.

Mechanism graphs

Mating-projection polarity topology (FUNCTION)

The fungal mating projection has a surrounding membrane, a polarized-growth tip, a basal region, septin structures at the neck, and a tip-localized polarisome.

Subject	Predicate	Object	Evidence
mating projection membrane	surrounds	mating projection	`GO:0070250` GO:0070250 identifies the mating projection membrane.
mating projection tip membrane	is part of	mating projection tip	`GO:0070867` GO:0070867 identifies the membrane portion surrounding the mating projection tip.
mating projection tip	is part of	mating projection	`GO:0043332` GO:0043332 identifies the mating projection tip as a part of the mating projection.
mating projection base	is part of	mating projection	`GO:0001400` GO:0001400 identifies the mating projection base as a part of the mating projection.
mating projection septin ring	is part of	mating projection	`GO:0032175` GO:0032175 identifies the mating projection septin ring as a part of the mating projection. `DOI:10.1128/EC.4.9.1503-1512.2005` Douglas et al. 2005 reviewed septin structures at yeast shmoo necks.
mating projection septin band	is part of	mating projection	`GO:0032162` GO:0032162 identifies the mating projection septin band as a part of the mating projection.
mating projection tip polarisome	localizes to	mating projection tip	`GO:0031563` GO:0031563 identifies the polarisome localized to the mating projection tip. `DOI:10.1083/jcb.200307065` Bidlingmaier and Snyder 2004 studied Spa2, Pea2, and Bni1 polarisome components in yeast mating projections.

Discussions

INTERPRETATION (RESOLVED): Keep polarisome and septin proteins on their own structure records rather than duplicating them as mating projection components. GO:0005937 identifies the whole projection, while GO child terms identify localized membrane, tip, base, septin, and polarisome substructures. This projection-level record links those substructures with has_part and graph edges while leaving their molecular subunits on the polarisome and septin records.

Evidence

GO:0005937 Gene Ontology cellular-component term for the mating projection.
GO:0120025 Gene Ontology cellular-component parent term for plasma membrane-bounded cell projections.
GO:0070250 Gene Ontology cellular-component term for the mating projection membrane.
GO:0043332 Gene Ontology cellular-component term for the mating projection tip.
GO:0001400 Gene Ontology cellular-component term for the mating projection base.
GO:0032175 Gene Ontology cellular-component term for the mating projection septin ring.
GO:0032162 Gene Ontology cellular-component term for the mating projection septin band.
GO:0031563 Gene Ontology cellular-component term for the mating projection tip polarisome.
GO:0070867 Gene Ontology cellular-component term for the mating projection tip membrane.
DOI:10.1091/mbc.3.4.429 Read et al. 1992, 'Actin- and tubulin-dependent functions during Saccharomyces cerevisiae mating projection formation', Molecular Biology of the Cell.
DOI:10.1083/jcb.200307065 Bidlingmaier and Snyder 2004, 'Regulation of polarized growth initiation and termination cycles by the polarisome and Cdc42 regulators', Journal of Cell Biology.
DOI:10.1128/EC.4.9.1503-1512.2005 Douglas et al. 2005, 'Septin function in yeast model systems and pathogenic fungi', Eukaryotic Cell.
DOI:10.1083/jcb.135.3.725 Valtz and Herskowitz 1996, 'Pea2 protein of yeast is localized to sites of polarized growth and is required for efficient mating and bipolar budding', Journal of Cell Biology.

Curation history

2026-09-28T13:23:24Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-28T13:26:29Z codex · EXPANDED_RECORD — Moved the mating projection to APPENDAGE, added GO-backed shmoo synonymy, parentage, substructures, Saccharomyces distribution, a polarized-growth function, DOI evidence, a nonmechanistic projection topology graph, and a localized-complex boundary decision.
2026-09-28T13:42:13Z codex · ADDRESSED_REVIEW — Resolved #1726 by adding the GO:0070867 mating projection tip membrane to the topology graph.

Source: data/structures/appendage/mating_projection.yaml