Phosphoprotein phosphatase inhibitor-2 is phosphorylated at both serine and threonine residues in mouse diaphragm.
Phosphoprotein phosphatase inhibitor-2 (i-2) was rapidly isolated from mouse diaphragm extracts by the use of specific antibodies. The i-2 so obtained was associated with ATP-Mg and FA/GSK-3 dependent phosphatase activity, supporting the idea that i-2 is in fact a component of this form of phosphatase. Inhibitor-2 isolated from diaphragms incubated with [32P]phosphate contained both phosphoserine (approximately 90%) and phosphothreonine (approximately 10%). Therefore, i-2 is multiply phosphorylated in mouse diaphragm and the potential exists for control of the ATP-Mg-dependent phosphatase via multiple phosphorylation sites in vivo.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003964:Diaphragm / Q000378:metabolism; D007163:Immunosorbent Techniques; D008297:Male; D051379:Mice; D008970:Molecular Weight; D009124:Muscle Proteins / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D010766:Phosphorylation; D011506:Proteins / Q000378:metabolism*; D012694:Serine / Q000378:metabolism*; D013912:Threonine / Q000378:metabolism*; D000097847:Protein Phosphatase Inhibitory Proteins
D000255:Adenosine Triphosphate; D000596:Amino Acids; D009124:Muscle Proteins; D011506:Proteins; D012694:Serine; D013912:Threonine; C024833:protein phosphatase inhibitor-2; D000097847:Protein Phosphatase Inhibitory Proteins