Proteolytic processing of the Drosophila Spätzle protein by easter generates a dimeric NGF-like molecule with ventralising activity.
Biochemical interactions underlying the generation of the ventralising signal during Drosophila embryogenesis were investigated by the expression of recombinant Easter and Spätzle proteins. An active form of Easter protease cleaves the Spätzle protein, generating a carboxyterminal polypeptide fragment which, when microinjected into the perivitelline space of a spätzle deficient embryo, directs production of ventrolateral pattern elements. This Spätzle carboxyterminal fragment is a disulfide-linked dimer and modelling suggests that the core disulfide bonds and dimer arrangement of this fragment are highly similar to vertebrate nerve growth factor. Thus Spätzle is a member of a new family of neurotrophin-like signalling molecules in invertebrate development.
DeLotto
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Department of Genetics, University of Copenhagen, Oster Farimagsgade 2A, DK-1353, Copenhagen K, Denmark.
DeLotto
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D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D019281:Dimerization; D004220:Disulfides / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D010641:Phenotype; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism*; D018411:Spodoptera; D014817:Vitelline Membrane / Q000378:metabolism
D004220:Disulfides; D029721:Drosophila Proteins; D019476:Insect Proteins; D008024:Ligands; D009414:Nerve Growth Factors; D010446:Peptide Fragments; D011994:Recombinant Proteins; C086179:spz protein, Drosophila; D012697:Serine Endopeptidases; C078099:ea protein, Drosophila