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Studies on Functions of the 63-kDa A- and 74-kDa B' gulatory Subunits in Human Erythrocyte Protein Phosphatase 2A: Dissociation and Reassociation of the Subunits
- Source :
- Journal of Biochemistry. 126:1127-1135
- Publication Year :
- 1999
- Publisher :
- Oxford University Press (OUP), 1999.
-
Abstract
- A heterodimeric form, CA, of protein-serine/threonine phosphatase (PP) 2A purified from human erythrocytes was dissociated into a 34-kDa catalytic subunit C and 63-kDa inactive subunit A by Sephacryl S-200 gel filtration in the presence of 6 M urea. Reassociation of the C- and A-subunits in the absence of urea suppressed the PP activity of the C subunit toward phosphorylase a, P-H2B histone, and P-H1 histone in the presence or absence of 20 mM MnCl(2) or 50 mM Mg(CH(3)COO)(2), but stimulated the PP activity toward P-H1 histone in the presence of 200 mM NaCl and the Mn(2+)-dependent protein-tyrosine phosphatase (PTP) activity toward P-Tyr-Glu copolymers. The 74-kDa inactive B'(delta) subunit was isolated from a heterotrimeric form, CAB'(delta), of PP2A partially purified from human erythrocytes, by heparin-Sepharose column chromatography. The B'(delta) subunit reassociated with CA and suppressed the PP- and PTP-activities of CA. The B'(delta) subunit did not associate with the isolated C subunit directly, and had no effect on the activities of the C subunit, indicating that the A subunit is essential for the association of the B'(delta) subunit with CA and the resulting suppression of the PP- and PTP-activities.
- Subjects :
- Manganese
Erythrocytes
Protein Conformation
Protein subunit
Phosphatase
General Medicine
Protein phosphatase 2
Biology
Biochemistry
Molecular biology
Peptide Fragments
Molecular Weight
G12/G13 alpha subunits
Heterotrimeric G protein
Chromatography, Gel
Phosphoprotein Phosphatases
Humans
Electrophoresis, Polyacrylamide Gel
Protein quaternary structure
Protein Phosphatase 2
Threonine
Chromatography column
Molecular Biology
Subjects
Details
- ISSN :
- 0021924X
- Volume :
- 126
- Database :
- OpenAIRE
- Journal :
- Journal of Biochemistry
- Accession number :
- edsair.doi.dedup.....7d632ad16468be015c3cbe5a4a330be2