. "Human T lymphoblastoid cell line CEM-ON belongs to a helper/inducer subclass and secretes M-CSF into medium constitutively. We have isolated a full-length cDNA clone for this factor from a cDNA library of this cell line. The cDNA was 2.5 kb and coded for a 554 amino acid polypeptide precursor including signal sequence. The Northern blot analysis showed that the major transcript of M-CSF is about 4.2 kb. We have studied the expression of not only the wild type plasmid, but also the five C-terminal deletion mutants encoding N-terminal 154, 163, 170, 177, and 185 amino acid residues in monkey COS-1 cells. The results showed that at least C-terminal 377 amino acid residues of human M-CSF are not essential to manifest the in vitro biological activity on murine bone marrow cells." . . . "Biochem. Biophys. Res. Commun." . "Takahashi M." . "Hirai Y." . "Nishida T." . "Nakai S." . "Takano M." . "Hirato T." . "Nagamura K." . "Kamogashira T." . "1989"^^ . "892-901" . "Amino-terminal region of human macrophage colony-stimulating factor (M-CSF) is sufficient for its in vitro biological activity: molecular cloning and expression of carboxyl-terminal deletion mutants of human M-CSF." . "161" . "doi:10.1016/0006-291X(89)92683-1" .