Rojas-Cabañeros, Jose MariaOliva-Martinez, Jose LuisSantos, Eugenio2019-01-112019-01-112011-03Genes Cancer. 2011;2(3):298-3051947-6019http://hdl.handle.net/20.500.12105/7002The Son of Sevenless (Sos) factors were originally discovered 2 decades ago as specialized Ras activators in signaling pathways controlling the process of R7 cell development in the eye of Drosophila melanogaster. The 2 known members of the mammalian Sos family (Sos1 and Sos2) code for ubiquitously expressed, highly homologous (69% overall) proteins involved in coupling signals originated by cell surface receptor tyrosine kinases (RTKs) to downstream, Ras-dependent mitogenic signaling pathways. Mechanistically, the Sos proteins function as enzymatic factors interacting with Ras proteins in response to upstream stimuli to promote guanine nucleotide exchange (GDP/GTP) and subsequent formation of the active Ras-GTP complex. In this review, we summarize current knowledge on structural, regulatory, and functional aspects of the Sos family, focusing on specific aspects of Sos biology such as structure-function relationship, crosstalk with different signaling pathways, and in vivo functional significance as deduced from phenotypic characterization of Sos knockout mice and human genetic syndromes caused by germline hSos1 mutations.engVoRRTKRasRas-GEFSossignalingAtribución-4.0 Internacional2177950023298-30510.1177/19476019114080781947-6027Genes & canceropen access