Identification and partial characterization of a latent ATP, Mg-dependent protein phosphatase in rabbit skeletal muscle cytosol
- 1 January 1989
- journal article
- research article
- Published by Springer Nature in Molecular and Cellular Biochemistry
- Vol. 87 (1) , 31-39
- https://doi.org/10.1007/bf00421080
Abstract
Fractionation of rabbit skeletal muscle cytosol on Aminohexyl-Sepharose has resulted in the identification of a latent ATP, Mg-dependent protein phosphatase whose catalytic subunit is in the active conformation, but is inhibited by the presence of more than one modulator unit. The partially purified enzyme is converted to an inactive, kinase FA-dependent form upon incubation at 30°C unless modulator-specific polyclonal antibodies are added to the preparation. The immunoglobulins also relieve the inhibition which is responsible for the low basal phosphatase activity of the enzyme, and they counteract all of the heat-stable inhibitor activity present in the preparation. Addition of free catalytic subunit abolishes the inhibition of the latent enzyme in a dose-dependent way, but cannot prevent the inactivation process. The inactivated phosphatase and the original latent enzyme exhibit the same apparent M r in sucrose density-gradient centrifugation (70 000) and in gel filtration (110 000).This publication has 55 references indexed in Scilit:
- Insulin induces activation and translocation of protein kinase FA (a multifunctional protein phosphatase activator) in human plateletBiochemical and Biophysical Research Communications, 1988
- The type-1 protein phosphatase activating factor FA is a membrane-associated protein kinase in brain, liver, heart and musclesBiochemical and Biophysical Research Communications, 1987
- The ATP,Mg-dependent phosphatase: Role of Mg ions in the expression of the phosphorylase phosphatase activityBiochemical and Biophysical Research Communications, 1986
- Phosphorylase a is an allosteric inhibitor of the glycogen and microsomal forms of rat hepatic protein phosphatase‐1FEBS Letters, 1986
- Isolation and characterization of two 70 kDa modulator-complexes from rabbit skeletal muscleBiochemical and Biophysical Research Communications, 1986
- Purification of a latent protein phosphatase from rabbit skeletal muscleBiochemical and Biophysical Research Communications, 1984
- Subunit structure and activation of inactive phosphorylase phosphataseBiochemistry, 1983
- Conversion of active protein phosphatase to the ATP‐Mg‐dependent enzyme form by inhibitor‐2FEBS Letters, 1981
- Effect of epinephrine and insulin on the phosphorylation of phosphorylase phosphatase inhibitor 1 in perfused rat skeletal muscleFEBS Letters, 1980
- The hormonal control of glycogen metabolism: dephosphorylation of protein phosphatase inhibitor‐1 in vivo in response to insulinFEBS Letters, 1980