title: Structure and expression of the mRNA for murine granulocyte-macrophage colony stimulating factor.
abstract: A cDNA containing a virtually complete copy of the mRNA for the haemopoietic growth regulator, granulocyte-macrophage colony stimulating factor (GM-CSF), has been isolated from a murine T lymphocyte cDNA library. When a eukaryotic expression vector with this cDNA coupled to the SV40 late promoter was introduced into simian COS cells, significant quantities of GM-CSF were secreted. Since all of the biological activities previously ascribed to highly purified GM-CSF were exhibited in the COS cell-derived GM-CSF, all of these activities are intrinsic to the product of a single gene. There are two potential translational initiation codons in the GM-CSF mRNA; the first is buried in the stem and the second located in the loop of a very stable hairpin structure. Expression studies using deletion derivatives of the cDNA indicated that the second AUG is able to initiate the translation and secretion of GM-CSF. The amino acid sequence of the leader peptide is rather atypical for a secreted protein and we speculate that molecules which initiate at the first AUG might exist as integral membrane proteins whereas those initiating at the second are secreted.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001681:Biological Assay; D003001:Cloning, Molecular; D003115:Colony-Stimulating Factors / Q000235:genetics*; D005786:Gene Expression Regulation; D006098:Granulocytes; D008264:Macrophages; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D009690:Nucleic Acid Conformation; D010455:Peptides / Q000235:genetics; D014176:Protein Biosynthesis; D021382:Protein Sorting Signals; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D003115:Colony-Stimulating Factors; D008565:Membrane Proteins; D010455:Peptides; D021382:Protein Sorting Signals; D012333:RNA, Messenger