Karlovich, Chris A.Bonfini, LauraMcCollam, LindaRogge, Ronald D.Daga, AndreaCzech, Michael P.Banerjee, Utpal2022-08-232022-08-231995-04-282008-10-09<p>Science. 1995 Apr 28;268(5210):576-9.</p>0036-8075 (Print)10.1126/science.77251067725106https://hdl.handle.net/20.500.14038/33940The Son of sevenless (Sos) protein functions as a guanine nucleotide transfer factor for Ras and interacts with the receptor tyrosine kinase Sevenless through the protein Drk, a homolog of mammalian Grb2. In vivo structure-function analysis revealed that the amino terminus of Sos was essential for its function in flies. A molecule lacking the amino terminus was a potent dominant negative. In contrast, a Sos fragment lacking the Drk binding sites was functional and its activity was dependent on the presence of the Sevenless receptor. Furthermore, membrane localization of Sos was independent of Drk. A possible role for Drk as an activator of Sos is discussed and a Drk-independent interaction between Sos and Sevenless is proposed that is likely mediated by the pleckstrin homology domain within the amino terminus.en-USJournal Articlehttps://escholarship.umassmed.edu/gsbs_sp/592646777gsbs_sp/592