The highest activity of glycerophosphocholine phosphodiesterase (EC 3.1.4.2) in subcellular fractions of rat forebrain was found in the microsomal fraction though significant amounts were found in fractions containing plasma membranes. With the use of Ca(2+)/EGTA and Ca(2+)/EDTA buffers it was shown that very low concentrations of free Ca(2+) (EC(50)approx. 10(-9)m) could activate the enzyme.

The subcellular localization of insulin signaling proteins is altered by various stimuli such as insulin, insulin-like growth factor I, and oxidative stress and is thought to be an important mechanism that can influence intracellular signal transduction and cellular function. This study examined the possibility that exercise may also alter the subcellular localization of insulin signaling prote...