A short linear motif, conserved from yeast to human, binds to members of the Spa2 family of cortical scaffold proteins.

ABSTRACT: Tip growth is closely tied to fungal pathogenicity. Budding yeast Spa2 (the homolog of GIT1 and GIT2 in mammals), a multi-domain protein and member of the polarisome, orchestrates tip growth in yeasts and other fungi. 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. AlphaFold predictions suggest that these initially unstructured motifs adopt an α-helical conformation upon binding to the hydrophobic cleft in the N-terminal domain of Spa2. Altering the predicted key contact residues in either Spa2 or the motif reduces complex stability. Such mutations also cause mis-localization of Msb3, Msb4 and Ste7 within the cell. Deleting the motif in Msb3 or M

SUBMITTER: Bareis L 

PROVIDER: S-EPMC12831199 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature