Morphological changes of BM-N4 cells induced by bombyxin, an insulin-related peptide of Bombyx mori.
Bombyxin is a brain secretory peptide of the silkmoth Bombyx mori whose amino acid sequence shows considerable sequence homology with vertebrate insulin-family peptides. We found that a Bombyx cell line, named BM-N4, showed morphological changes when bombyxin was added to the culture medium at doses as low as 10(-10) M. Bombyxin-treated cells displayed a series of morphological modifications: 1 to 2 weeks after introduction of bombyxin, the cells increased in size, then they trended to aggregate, or took a spindle shape. These changes of the cells were bombyxin specific, not induced by other vertebrate insulin-family peptides. To prove that these modifications of the cells are mediated by receptors on the cell surface of the cells, we performed a receptor binding assay using 125I-labeled bombyxin. Scatchard analysis of the binding assay indicated that this cell line has a single class of receptors for bombyxin with a Kd = 2.36 +/- 0.56 nM and each cell has 15,800 +/- 1400 binding sites on the cell surface.
D000818:Animals; D012831:Bombyx / Q000033:anatomy & histology / Q000737:chemistry*; D002460:Cell Line; D003470:Culture Media; D007301:Insect Hormones / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D009479:Neuropeptides / Q000494:pharmacology*; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000032:analysis; D017386:Sequence Homology, Amino Acid
D003470:Culture Media; D007301:Insect Hormones; D007328:Insulin; D009479:Neuropeptides; D011956:Receptors, Cell Surface; C096422:bombyxin receptor; C075028:bombyxins