Martelli A M, Bareggi R, Cocco L, Manzoli F A
Dipartimento di Morfologia Umana Normale, Trieste, Italy.
Biochem Biophys Res Commun. 1996 Jan 5;218(1):182-6. doi: 10.1006/bbrc.1996.0032.
The nonhydrolyzable GTP analogue GTP-gamma-S was capable of stimulating in vitro phosphorylation of polyphosphoinositides in isolated nuclei prepared from mouse erythroleukemia cells. On the contrary, GDP-beta-S was ineffective. The stimulation was not detectable when nuclei were prepared from erythroleukemia cells induced to differentiate by exposure to dimethyl sulfoxide. Both nuclear phosphomonoesterase and phospholipase C activities were not influenced by GTP-gamma-S. Our results point to the likelihood that nuclear phosphoinositide kinases might be regulated by a GTP-binding protein.
