Ste7

Back to main model page

About Ste7

Ste7 is hyperphosphorylated in response to pheromone. This requires a functioning Ste7, so presumably it is phosphorylated by Fus3/Kss1. Zhou et al. 1993 PMID 8455599

Ste7 is phosphorylated at threonine 363 by Ste11. Neiman and Herskowitz 1994 PMID 8159759

Ste7 activation requires phosphorylation at serine 359 and threonine 363. Zheng and Guan 1994 PMID 8131746

Prior to pheromone stimulation, Ste7-GFP (overexpressed from the Gal promoter) is dispersed evenly throughout the cytoplasm. 2 hours after pheromone treatment, Ste7-GFP is localized to the shmoo tip. van Drogen et al. 2001 PMID 11781566

Ste7 mutant S368P is constitutively active in the absence of pheromone, but its activity is increased upon treatment with pheromone. Ste7(S368P) activity still depends on Ste11. The mutant may be a better substrate for Ste11 or a worse substrate for phosphatase. Yashar et al. 1995 PMID 8524219

Ste7 is phosphorylated by Fus3 in vitro at S105, T116, S130, T137, T149, S167, and S471. Meleri et al. 2004 PMID 15456892

Ste7(S359E T363E) causes consitutive activation of the filamentous growth response, but not the pheromone response. Meleri et al. 2004 PMID 15456892
- In vitro Ste7(S359E T363E) is able to phosphorylate both Fus3 and Kss1.
- In vivo, Kss1 is phosphorylated but this constitutive Ste7 mutant, but Fus3 is not. This effect is not changed when the Ste7's 7 feedback phosphorylation sites are mutated to glutamates or alanines (Ste7-E₇ and Ste7-A₇).

Fluorescently-tagged Ste7, expressed at wild-type levels, is largely cytoplasmic in the absence and presence of pheromone. Maeder et al. 2007 PMID 17952059

Ste7(Ste5_site, MAPK_site, S359_T363~none~pS~pSpT)

Ste7(Ste5_site, MAPK_site, S359_T363~none) Ste7_tot_conc