Identification of the separate domains in the hepatic glycogen-targeting subunit of protein phosphatase 1 that interact with phosphorylase a, glycogen and protein phosphatase 1
Cg. Armstrong et al., Identification of the separate domains in the hepatic glycogen-targeting subunit of protein phosphatase 1 that interact with phosphorylase a, glycogen and protein phosphatase 1, BIOCHEM J, 336, 1998, pp. 699-704
Deletion and mutational analyses of the rat liver glycogen-targeting subuni
t (G(L)) of protein phosphatase 1 (PP1) have identified three separate doma
ins that are responsible for binding of PP1, glycogen and phosphorylase a.
The glycogen-binding domain spans the centre of G(L) between residues 144 a
nd 231 and appears to be distinct from the glycogen-binding (storage) site
of phosphorylase. The regulatory high-affinity binding site for phosphoryla
se a lies in the 16 amino acids at the C-terminus of G(L). The PP1-binding
domain is deduced to comprise the -RVXF- motif [Egloff, Johnson, Moorhead,
Cohen and Barford (1997) EMBO J. 16, 1876-1887] located at residues 61-64 o
f G(L) and preceding lysine residues at positions 56, 57 and 59. A possible
approach for increasing glycogen synthesis in certain disorders is discuss
ed.