title: Purification and properties of the guanine nucleotide exchange factor (GEF) from HeLa cells and its role in the initiation of protein synthesis.
abstract: A guanine nucleotide exchange factor (GEF), catalyzing the exchange of GDP bound to initiation factor eIF-2 for GTP, has been isolated from S3 HeLa cells as the eIF-2 X GEF complex and extensively purified by procedures originally developed for purification of GEF from rabbit reticulocytes. The HeLa cell factor resembles rabbit reticulocyte eIF-2 X GEF in polypeptide composition, catalytic activity, and inactivation by alpha-phosphorylated eIF-2.
mesh_terms: D000818:Animals; D002384:Catalysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004591:Electrophoresis, Polyacrylamide Gel; D015852:Eukaryotic Initiation Factor-2; D020662:Guanine Nucleotide Exchange Factors; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006367:HeLa Cells / Q000032:analysis; D006801:Humans; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism
chemical_list: D015852:Eukaryotic Initiation Factor-2; D020662:Guanine Nucleotide Exchange Factors; D010448:Peptide Initiation Factors; D011506:Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate