Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Automatic assignment of GO terms using logical inference, based on on inter-ontology links
The cortical localization of the microtubule orientation protein, Kar9p, is dependent upon actin and proteins required for polarization.
Polarized growth controls cell shape and bipolar bud site selection in Saccharomyces cerevisiae.
Yeast formins regulate cell polarity by controlling the assembly of actin cables.
Spa2p functions as a scaffold-like protein to recruit the Mpk1p MAP kinase module to sites of polarized growth.
Actin recovery and bud emergence in osmotically stressed cells requires the conserved actin interacting mitogen-activated protein kinase kinase kinase Ssk2p/MTK1 and the scaffold protein Spa2p.
Regulation of cell polarity by interactions of Msb3 and Msb4 with Cdc42 and polarisome components.
Proteome survey reveals modularity of the yeast cell machinery.
Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.
Importance of polarisome proteins in reorganization of actin cytoskeleton at low pH in Saccharomyces cerevisiae.
Modular coherence of protein dynamics in yeast cell polarity system.
Spatial segregation of polarity factors into distinct cortical clusters is required for cell polarity control.
The SPA2 protein of yeast localizes to sites of cell growth.
The social and structural architecture of the yeast protein interactome.
Spa2 remodels ADP-actin via molecular condensation under glucose starvation.
Oligomerization and exocyst coupling underlie Spa2-mediated focusing of polarized growth in fission yeast.
A short linear motif, conserved from yeast to human, binds to members of the Spa2 family of cortical scaffold proteins.
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Spa2 SHD1 binds a conserved short linear motif in Msb3, Msb4, Ste7, and Mkk1, refining the direct motif-level basis for Spa2 recruitment of RabGAP and MAPK-pathway partners.
"We identified a conserved short linear motif in the Rab GTPase-activating proteins (RabGAPs) Msb3 and Msb4, and the MAP kinase kinases Ste7 and Mkk1, which mediates their interaction with Spa2."
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A proteome-wide search in the same study identified Dse3 as an additional candidate Spa2-binding partner.
"A search for functional motifs in conformationally flexible regions of all yeast proteins identified Dse3 as a novel Spa2-binding partner."
Identification of genes required for normal pheromone-induced cell polarization in Saccharomyces cerevisiae.
Pea2 protein of yeast is localized to sites of polarized growth and is required for efficient mating and bipolar budding.
Dissection of filamentous growth by transposon mutagenesis in Saccharomyces cerevisiae.
A small conserved domain in the yeast Spa2p is necessary and sufficient for its polarized localization.
The Spa2-related protein, Sph1p, is important for polarized growth in yeast.
Rho1p-Bni1p-Spa2p interactions: implication in localization of Bni1p at the bud site and regulation of the actin cytoskeleton in Saccharomyces cerevisiae.
Spa2p interacts with cell polarity proteins and signaling components involved in yeast cell morphogenesis.
Falcon (Edison) deep research synthesis: functional annotation of S. cerevisiae SPA2 (UniProt P23201)
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SPA2/YLL021W encodes Spa2, a polarisome scaffold protein that organizes
polarized growth and mating projection formation rather than acting as an
enzyme; it is a central scaffold coordinating recruitment of other polarisome
components (Bni1, Bud6, Pea2).
"Spa2 is a central scaffold that coordinates recruitment/organization of other polarisome components (commonly including Bni1, Bud6, Pea2) and thereby promotes focal polarization."
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During pheromone response, Spa2 is required for focal (narrow) polarization
of the polarisome at the shmoo tip via an ordered SHD-dependent pathway that
forms a positive feedback loop.
"Mechanistically, Lawson et al. (2022) provide evidence consistent with an ordered pathway in which an N-terminal Spa2 homology domain (SHD) recruits Msb3/4, promoting Sec4-dependent delivery of Bud6 to the polarisome, where Bud6 stimulates the formin Bni1 to generate actin cables; actin-dependent delivery then supports additional Spa2 accumulation, completing a positive feedback loop that sharpens focal polarization."
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Spa2 is recruited to the division site in late cell cycle and directly binds
cytokinetic factors Cyk3 and Hof1, coordinating incorporation of the chitin
synthase Chs2 into the cytokinetic machinery for primary septum formation.
"Foltman et al. (2018) show Spa2 is recruited to the division site in late cell cycle and directly binds cytokinetic factors, including **Cyk3** and **Hof1**, via Spa2 N-terminal regions containing Spa2 homology domains."
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Under glucose starvation Spa2 acts as a nucleotide-state-specific actin
remodeler, nucleating ADP-actin via a dimeric core (aa 281-535) and bundling
ADP-F-actin via an N-terminal IDR-driven condensation, relocalizing from the
bud tip to filamentous structures overlapping actin cables.
"Spa2 promotes rapid **ADP-actin monomer nucleation** via a dimeric core region (aa 281–535) and bundles ADP-F-actin through an N-terminal IDR-driven condensation (“wetting”) process, dependent on the actin D-loop."
Electronic Gene Ontology annotations created by ARBA machine learning models
YFR016c/Aip5 is part of an actin nucleation complex in yeast.
Cell polarity protein Spa2 coordinates Chs2 incorporation at the division site in budding yeast.
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Budding-yeast Spa2 is recruited to the cleavage site where it cooperates with secretory vesicle and actomyosin-ring factors to promote Chs2 incorporation into ingression progression complexes.
"Our data indicate that Spa2 is recruited to the cleavage site to co-operate with the secretory vesicle system and particular actomyosin ring components to promote the incorporation of Chs2 into the so-called 'ingression progression complexes' during cytokinesis in budding yeast."
Polarisome scaffolder Spa2-mediated macromolecular condensation of Aip5 for actin polymerization.
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Spa2 regulates the dynamics and reversibility of Aip5 condensates by liquid-liquid phase separation in vitro and in vivo.
"The molecular dynamics and reversibility of Aip5 condensates are regulated by scaffolding protein Spa2 via liquid-liquid phase separation both in vitro and in vivo."
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Loss of Spa2 worsens Aip5 condensate stress behavior and disrupts actin-cable structures under stress.
"In the absence of Spa2, Aip5 condensates hamper cell growth and actin cable structures under stress treatment."
The Cdc15 and Imp2 SH3 domains cooperatively scaffold a network of proteins that redundantly ensure efficient cell division in fission yeast.