Membrane-bound Nucleotide Research Articles

Abstract SY24-03: The signaling landscape of oncogenic ras

Abstract Ras proteins are highly conserved membrane-bound nucleotide binding proteins. They are essential for the transduction of diverse extracellular signals that control cell growth, and abnormal activation of Ras proteins is implicated in the development of several types of human cancers. It is now well established that Ras proteins control cell growth through the activation of multiple effector pathways. These pathways form a signaling network that enables the cell to interpret biological inputs in a context-dependent manner. I will describe our efforts to define a molecular framework for the regulation of Ras-dependent signal output and to understand how this output is modified in cancer cells. Citation Format: Dafna Bar-Sagi. The signaling landscape of oncogenic ras [abstract]. In: Proceedings of the AACR 101st Annual Meeting 2010; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr SY24-03

Binding of <sup>14</sup>C-ADP by Thrombasthenic Platelet Membranes

We have measured the binding of 14C-ADP to isolated human platelet membranes by a technique using 0.8-mum Millipore filters to separate unbound tracer from membrane-bound nucleotide. The binding was dependent on the time of incubation and on the nucleotide concentration in the medium. The affinity constant was found to be comprised between 0.35 x 10(6) and 0.55 x 10 (6) M-1. Platelet membranes prepared from different thrombasthenic patients bound 14C-ADP with the same kinetic parameters as those from normal subjects. The affinity constant as determined for two of these thrombasthenic platelet membrane preparations was in the normal range.