- Ste4 is multiply phosphorylated in a pheromone dependent manner, but these phosphorylations have no detectable effect on response. Li et al. 1998 PMID 9671029
- Ste5 anf Far1 both bind to Ste4 with homologous RING-H2 domains, suggesting that both Far1 and Ste5 would not be able to simultaneoulsy bind a single molecule of Ste4. Sette et al. 2000 PMID 11071925
- Sucrose density gradient fractionation suggests that the majority of Ste4 is associated with the plasma membrane and not other internal membranes. Song et al. 1996 PMID 8702760
- Renografin density gradient fractionation suggests that about 30% of Ste4 is in the soluble fraction, 40% is associated with the plasma membrane, and 30% is associated with other parts of the pellet. Hirschman et al. 1997 PMID 8995254
- Pma1 was used as a marker for the plasma membrane fractions.
- The Renografin concentrations used have an ionic strength equivalent to 0.5 M NaCl. This could disrupt weak protein association with the plasma membrane.
- Ste18 is farnesylated (prenylated) at C107, and palmitoylated (thioacylated) at C106. Manahan et al. 2000 PMID 10712512
- Farnesylation at C107 is required for palmitoylation at C106. Manahan et al. 2000 PMID 10712512
- Defect in palmitoylation results in compromised mating ability, and defect in farnesylation (which causes a defect in palmitoylation as well) results in a sterile phenotype. Manahan et al. 2000 PMID 10712512
- Total amount of G protein per cell was measured by quantitative Western blots and fluorescent quantification to be 10000 per cell. Yi et al. 2003 PMID 12960402
- Total Ste4:Ste18 concentration of 0.2 nM (which equates to ~7800 moleculse per cell for a 5 μm cell) was used in a model (no source). Hao et al. 2003 PMID 12968019
- Ste4 and Ste18 have a half-life of greater than 3 hours. Hirschman et al. 1997 PMID 8995254
Pheromone/Receptor/G protein interactions
Ste4:Ste18/Ste5 interactions and Ste5 dimerization/oligomerization
Protein dilution/synthesis due to cell growth