mating projection tip

GO:0043332 · Other · Subcellular region · Proposed

The apex of the mating projection in unicellular fungi exposed to mating pheromone; site of polarized growth. [GO:0043332]

Synonyms: shmoo tip; conjugation tube tip

Part of: mating projection (GO:0005937)

Has part: mating projection tip membrane (GO:0070867); mating projection tip polarisome (GO:0031563); mating projection actin fusion focus (GO:1990819)

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — VARIABLE: Haploid budding-yeast cells extend Spa2-positive projection tips during pheromone-induced mating projection formation. [DOI:10.1091/mbc.3.4.429]
NCBITaxon:4896 Schizosaccharomyces pombe — VARIABLE: Fission-yeast mating cells form a focused actin aster at the fusion site of the mating projection tip. [DOI:10.1083/jcb.201411124]

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model in which Spa2p segregates to mating projection tips in an actin-dependent projection-forming response. [DOI:10.1091/mbc.3.4.429]
NCBITaxon:4896 Schizosaccharomyces pombe — Fission-yeast model in which the actin fusion focus forms from formin-nucleated filaments at the fusion site. [DOI:10.1083/jcb.201411124]

mating-projection tip polarized-growth site — The mating projection tip is the polarized apex of the pheromone-induced projection where membrane, polarisome, and actin-fusion structures organize growth and cell fusion.
- GO:0043332 GO:0043332 defines the mating projection tip as the projection apex and site of polarized growth.
- GO:0031563 GO:0031563 identifies a polarisome localized at the mating projection tip.
- GO:1990819 GO:1990819 identifies the actin fusion focus at the mating projection tip.
- DOI:10.1083/jcb.201411124 Dudin et al. 2015 connected the fission-yeast actin fusion focus with local cell-wall dissolution during cell fusion.
- DOI:10.1091/mbc.3.4.429 Read et al. 1992 tracked Spa2p segregation to Saccharomyces cerevisiae projection tips during mating projection formation.

The mating projection tip is the polarized apex of the mating projection and hosts tip-membrane, polarisome, and actin-fusion-focus substructures.

Subject	Predicate	Object	Evidence
mating projection tip	is part of	mating projection	`GO:0043332` GO:0043332 identifies the mating projection tip as part of the mating projection.
mating projection tip membrane	is part of	mating projection tip	`GO:0070867` GO:0070867 identifies the plasma-membrane portion surrounding a mating projection tip.
mating projection tip polarisome	localizes to	mating projection tip	`GO:0031563` GO:0031563 identifies the polarisome localized to the mating projection tip. `DOI:10.1091/mbc.3.4.429` Read et al. 1992 observed Spa2p segregation to mating projection tips in Saccharomyces cerevisiae.
mating projection actin fusion focus	is part of	mating projection tip	`GO:1990819` GO:1990819 identifies the actin fusion focus at the mating projection tip.
mating projection actin fusion focus	focalizes	cell wall dissolution	`DOI:10.1083/jcb.201411124` Dudin et al. 2015 showed that the actin fusion focus focalizes cell-wall dissolution within a broader synthesis zone.

INTERPRETATION (RESOLVED): Keep polarisome proteins, actin-fusion-focus proteins, and hydrolases on their own structure or protein records rather than duplicating them as direct mating projection tip components. GO:0043332 identifies the tip region, while GO:0031563 and GO:1990819 identify localized assemblies at that region. Those assemblies are linked as tip-localized structures here, leaving their protein constituents on complex-specific or ProteinTraitsMech records.

GO:0043332 Gene Ontology cellular-component term for the mating projection tip.
GO:0005937 Gene Ontology cellular-component term for the mating projection.
GO:0070867 Gene Ontology cellular-component term for the mating projection tip membrane.
GO:0031563 Gene Ontology cellular-component term for the mating projection tip polarisome.
GO:1990819 Gene Ontology cellular-component term for the mating projection actin fusion focus.
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:10.1083/jcb.201411124 Dudin et al. 2015, 'A formin-nucleated actin aster concentrates cell wall hydrolases for cell fusion in fission yeast', Journal of Cell Biology.
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.

2026-09-28T14:13:54Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-28T14:14:52Z codex · EXPANDED_RECORD — Added shmoo-tip synonymy, mating-projection parthood, exact GO child structures, Saccharomyces and Schizosaccharomyces examples, a polarized-growth-site function, DOI evidence, a nonmechanistic tip-localized-structure graph, and a localized machinery boundary decision.
2026-09-28T14:32:58Z codex · ADDRESSED_REVIEW — Resolved #1728 by switching the Saccharomyces projection-tip localization claims to direct Read et al. Spa2p tip evidence.