In vivo functional analysis of the Ras exchange factor son of sevenless
Biochemistry & Molecular Pharmacology
Graduate School of Biomedical Sciences; Department of Biology and Molecular Biology; Program in Molecular Medicine
Medical Subject Headings
Animals; Binding Sites; Cell Membrane; Drosophila; *Drosophila Proteins; Eye Proteins; Guanine Nucleotide Exchange Factors; Insect Hormones; Membrane Glycoproteins; Membrane Proteins; Photoreceptors, Invertebrate; Proteins; Receptor Protein-Tyrosine Kinases; Signal Transduction; Son of Sevenless Proteins; ras Guanine Nucleotide Exchange Factors
Life Sciences | Medicine and Health Sciences
The 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.
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Citation: Science. 1995 Apr 28;268(5210):576-9.
Science (New York, N.Y.)
Karlovich, Chris A.; Bonfini, Laura; McCollam, Linda; Rogge, Ronald D.; Daga, Andrea; Czech, Michael P.; and Banerjee, Utpal, "In vivo functional analysis of the Ras exchange factor son of sevenless" (1995). GSBS Student Publications. 592.