Characterization of magmas, a novel gene involved in gm-csf signal transduction

Abstract

Granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin 3 (IL-3) are two factors that affect the survival, growth and differentiation of hematopoietic cells. The receptors for these factors are comprised of an a subunit which is responsible for ligand specificity and a shared subunit known as the common b chain (bc). In order to identify genes uniquely responsive to one of these factors, we performed differential display on murine myeloid cell lines grown in either IL-3 or GM-CSF. One of the bands identified by differential display was shown on Northern blot to be rapidly induced when cells were switched from IL-3 to GM-CSF. Both human and murine cDNA and genomic DNA clones of this gene were isolated. A comparison of the encoded protein sequence showed that the murine cDNA and genomic DNA clones of this gene were isolated. A comparison of the encoded protein sequence showed that the murine and human genes were highly conserved. Analysis of the amino acid sequence of the protein did not reveal homology to any known functional domains. Growth factor dependent cell lines were electroporated with constitutively expressed sense and anti-sense cDNA constructs of the gene. Cells transfected with the sense construct proliferated similarly to untransfected cells when cultured in IL-3 or GM-CSF. Cells containing the antisense construct also grew normally in IL-3, but were not able to proliferate in the presence of GM-CSF. This novel gene has been functionally named Magmas for Mediator of Granulocyte Macrophage CSF signaling.