An ATPMg-dependent phosphorylase phosphatase was identified in vascular smooth muscle from bovine aorta. The smooth muscle enzyme, like the corresponding enzyme from striated muscle, exists as an inactive phosphatase (FC-enzyme) which can be activated by a protein, FA, in the presence of ATP and Mg2+. Moreover, smooth muscle FC is activatable by skeletal muscle FA and skeletal muscle FC can be activated by smooth muscle FA. The mode of activation of aortic FC by aortic FA is similar to that reported for the skeletal muscle proteins. In accord with earlier findings obtained with the skeletal muscle system, the activity of the aortic phosphatase is inhibited by a specific heat-stable modulator protein (previously called phosphatase inhibitor-2). Thus, the fundamental properties of arterial ATPMg-dependent phosphatase appear to be identical to those of its skeletal muscle counterpart which purportedly represents the major phosphorylase phosphatase in that tissue. Since glycogen phosphorylase is activated when vascular smooth muscle contracts, ATPMg-dependent protein phosphatase may participate in coordinating arterial metabolism and contractility.
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 1982 Sep 30|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology