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Specific interactions of PP2A and PP2A-like phosphatases with the yeast PTPA homologues, Ypa1 and Ypa2.
- Source :
-
The Biochemical journal [Biochem J] 2005 Feb 15; Vol. 386 (Pt 1), pp. 93-102. - Publication Year :
- 2005
-
Abstract
- To elucidate the specific biological role of the yeast homologues of PTPA (phosphatase 2A phosphatase activator), Ypa1 and Ypa2 (where Ypa stands for yeast phosphatase activator), in the regulation of PP2A (protein phosphatase 2A), we investigated the physical interaction of both Ypa proteins with the catalytic subunit of the different yeast PP2A-like phosphatases. Ypa1 interacts specifically with Pph3, Sit4 and Ppg1, whereas Ypa2 binds to Pph21 and Pph22. The Ypa1 and Ypa2 proteins do not compete with Tap42 (PP2A associating protein) for binding to PP2A family members. The interaction of the Ypa proteins with the catalytic subunit of PP2A-like phosphatases is direct and independent of other regulatory subunits, implicating a specific function for the different PP2A-Ypa complexes. Strikingly, the interaction of Ypa2 with yeast PP2A is promoted by the presence of Ypa1, suggesting a positive role of Ypa1 in the regulation of PP2A association with other interacting proteins. As in the mammalian system, all yeast PP2A-like enzymes associate as an inactive complex with Yme (yeast methyl esterase). Ypa1 as well as Ypa2 can reactivate all these inactive complexes, except Pph22-Yme. Ypa1 is the most potent activator of PP2A activity, suggesting that there is no direct correlation between activation potential and binding capacity.
- Subjects :
- Adaptor Proteins, Signal Transducing
Carboxylic Ester Hydrolases metabolism
Catalytic Domain
Enzyme Activation
Intracellular Signaling Peptides and Proteins
Multiprotein Complexes
Peptidylprolyl Isomerase
Phosphoprotein Phosphatases chemistry
Phosphorylation
Protein Binding
Protein Interaction Mapping
Protein Phosphatase 2
Protein Processing, Post-Translational
Protein Subunits
Recombinant Fusion Proteins chemistry
Recombinant Fusion Proteins metabolism
Saccharomyces cerevisiae Proteins chemistry
Sirolimus pharmacology
Structure-Activity Relationship
Two-Hybrid System Techniques
Phosphoprotein Phosphatases metabolism
Saccharomyces cerevisiae metabolism
Saccharomyces cerevisiae Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1470-8728
- Volume :
- 386
- Issue :
- Pt 1
- Database :
- MEDLINE
- Journal :
- The Biochemical journal
- Publication Type :
- Academic Journal
- Accession number :
- 15447631
- Full Text :
- https://doi.org/10.1042/BJ20040887