Ptc1 is a type Two C

phosphatase In biochemistry, a phosphatase is an enzyme that uses water to cleave a phosphoric acid Ester, monoester into a phosphate ion and an Alcohol (chemistry), alcohol. Because a phosphatase enzyme catalysis, catalyzes the hydrolysis of its Substrate ...

involved in the mating decision of yeast. Ptc1 competes with Fus3 for control of the 4 phosphorylation sites on the

scaffold protein In biology, scaffold proteins are crucial regulators of many key signalling pathways. Although scaffolds are not strictly defined in function, they are known to interact and/or bind with multiple members of a signalling pathway, tethering them in ...

Ste5. Presence of the

mating pheromone Sex pheromones are pheromones released by an organism to attract an individual of the same species, encourage them to mate with them, or perform some other function closely related with sexual reproduction. Sex pheromones specifically focus on ind ...

α-factor causes Ptc1 to be recruited to Ste5. This recruitment takes place via a 4 amino acid motif in the Ste5 phosphosites. Ptc1 is also involved in regulating the osmotic stress of yeast, especially via inactivation of Hog1, a member of the

MAPK A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of serine/threonine-specific protein kinases involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflamm ...

pathway. This inactivation occurred as a result of dephosphorylation of the phosphotheronine but not the phosphotyrosine residue in the phosphorylation lip of Hog1.{{cite journal , last=Warmka , first=Janel , date=Jan 2001 , title= Ptc1, a Type 2C Ser/Thr Phosphatase, Inactivates the HOG Pathway by Dephosphorylating the Mitogen-Activated Protein Kinase Hog1 , journal=Molecular and Cellular Biology , volume=21 , issue=1 , pages=51–60 , doi= 10.1128/MCB.21.1.51-60.2001, pmc=86567 , pmid=11113180 It can be localized to the cytoplasm and nucleus.

Biological Processes

Ptc1 is involved in the following biological processes: *Inactivation of MAPK activity in osmosensory signalling pathways *Mitochondrial inheritance *Pheromone-dependent signal transduction in conjugation with cellular fusion *Protein dephosphorylation *tRNA splicing via. Endonucleolytic cleavage and ligation

References

Enzymes of known structure