Abstract
We identified a human cDNA sequence encoding a polypeptide of 760 amino acids that shares 53% homology and 25.6% identity with the yeast DnaJ-like endoplasmic reticulum (ER) translocon component Sec63p. Three epitope-specific antisera revealed a protein of an apparent molecular mass of 83 kDa, both in human cell extracts and in dog pancreatic microsomes. Biochemical analyses show that it is an integral membrane protein of the rough ER, which has the DnaJ domain located in the ER lumen. The novel Sec63 protein could thus represent a key component of the mammalian ER protein translocation machinery.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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DNA, Complementary
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Dogs
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Endoplasmic Reticulum / chemistry
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Epitopes / chemistry
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Fungal Proteins / chemistry
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Fungal Proteins / genetics*
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HSP40 Heat-Shock Proteins
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HeLa Cells
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Heat-Shock Proteins / chemistry
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Heat-Shock Proteins / genetics*
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Humans
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Immune Sera
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Membrane Proteins / chemistry
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Membrane Proteins / genetics*
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Membrane Transport Proteins*
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Microsomes / chemistry
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Molecular Sequence Data
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Pancreas / chemistry
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Saccharomyces cerevisiae Proteins*
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Sequence Homology, Amino Acid
Substances
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DNA, Complementary
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Epitopes
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Fungal Proteins
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HSP40 Heat-Shock Proteins
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Heat-Shock Proteins
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Immune Sera
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Membrane Proteins
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Membrane Transport Proteins
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SEC63 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins