Abstract
The activation signal from tyrosine kinase receptors, such as the epidermal growth factor receptor (EGFR), is relayed via a highly conserved intracellular pathway involving Ras, Raf, and MAPK. In Drosophila, the EGFR and components of the intracellular pathway are broadly expressed, yet receptor activation evokes tissue-specific cell responses. Extracellular events that lead to receptor activation are one mechanism by which signaling is modulated. Here we show molecular and genetic evidence that Drosophila vein (vn) encodes a candidate EGFR ligand and that vn expression is spatially restricted. Consequently, vn may promote tissue-specific receptor activation. Unlike two other ligands, Gurken (Grk) and Spitz (Spi), which are transforming growth factor alpha-like proteins, Vn has both an immunoglobulin-like and an EGF-like domain. This combination of domains mirrors those in the vertebrate neuregulins that bind EGFR relatives.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Base Sequence
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Calcium-Calmodulin-Dependent Protein Kinases / genetics
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Calcium-Calmodulin-Dependent Protein Kinases / metabolism
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Cells, Cultured
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Cloning, Molecular
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Drosophila / cytology
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Drosophila / embryology
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Drosophila / genetics*
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Drosophila Proteins*
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Embryo, Nonmammalian / physiology
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Epidermal Growth Factor / genetics
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Epidermal Growth Factor / metabolism
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ErbB Receptors / genetics*
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ErbB Receptors / metabolism*
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Gene Expression Regulation, Developmental
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Genes, Lethal
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Glycoproteins / genetics
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Glycoproteins / metabolism
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Insect Proteins / genetics*
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Insect Proteins / metabolism*
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Larva / genetics
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Molecular Sequence Data
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Mutation
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Neuregulins
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Sequence Homology, Amino Acid
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Veins / growth & development
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Wings, Animal / blood supply
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Wings, Animal / embryology
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Wings, Animal / growth & development
Substances
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Drosophila Proteins
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Glycoproteins
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Insect Proteins
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Membrane Proteins
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Neuregulins
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spi protein, Drosophila
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vn protein, Drosophila
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Epidermal Growth Factor
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ErbB Receptors
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Calcium-Calmodulin-Dependent Protein Kinases