Abstract
The mec-5 and mec-9 genes encode putative extracellular proteins that allow a set of six touch receptor neurons in C. elegans to respond to gentle touch. MEC-5 is a collagen made by the epidermal cells that surround the touch cells. Mutations causing touch insensitivity affect the Gly-X-Y repeats of this collagen. mec-9 produces two transcripts, the larger of which is expressed in the touch cells and two PVD neurons. This transcript encodes a protein with 5 Kunitz-type protease inhibitor domains, 6 EGF-like repeats (2 of the Ca(2+)-binding type), and a glutamic acid-rich region. Missense mutations causing touch insensitivity affect both the EGF-like and Kunitz domains. Since mec-9 loss of function mutations dominantly enhance the touch insensitive phenotype of several mec-5 mutations, MEC-5 and MEC-9 may interact. We propose that these proteins provide an extracellular attachment point for the mechanosensory channels of the touch cells.
Publication types
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Comparative Study
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Research Support, U.S. Gov't, 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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Caenorhabditis elegans / genetics
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Caenorhabditis elegans / physiology*
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Caenorhabditis elegans Proteins*
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Collagen / genetics
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Collagen / physiology*
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Epistasis, Genetic
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Extracellular Matrix / physiology*
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Extracellular Matrix Proteins / chemistry
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Extracellular Matrix Proteins / genetics
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Extracellular Matrix Proteins / physiology*
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Fluorescent Dyes
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Genes, Helminth
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Genes, Recessive
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Genes, Reporter
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Helminth Proteins / chemistry
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Helminth Proteins / genetics
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Helminth Proteins / physiology*
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Mechanoreceptors / physiology*
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Neurons, Afferent / chemistry
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Neurons, Afferent / physiology*
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Protein Structure, Tertiary
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Recombinant Fusion Proteins / analysis
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Repetitive Sequences, Nucleic Acid
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Sequence Alignment
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Sequence Homology, Amino Acid
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Touch / physiology*
Substances
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Caenorhabditis elegans Proteins
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Extracellular Matrix Proteins
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Fluorescent Dyes
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Helminth Proteins
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MEC-5 protein, C elegans
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MEC-9 protein, C elegans
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Recombinant Fusion Proteins
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Collagen
Associated data
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GENBANK/U33918
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GENBANK/U33919
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GENBANK/U33933
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GENBANK/U33934