A homologue of the calcium-binding disulfide isomerase CaBP1 is expressed in the developing CNS of Drosophila melanogaster.
Previous studies identified a group of proteins localized to the endoplasmic reticulum (ER) that bind calcium and direct protein folding. Three of these proteins, CaBP1, CaBP2, and protein disulfide isomerase, have been purified from rat microsomes and analyzed biochemically. However, their function in vivo has not been determined. Here, we report the isolation of a homologue of the CaBP1 gene from the fruitfly Drosophila melanogaster (DmCaBP1). The predicted sequence of the Drosophila protein is very similar to that of rat CaBP1 and retains motifs thought to be functionally important in the mammalian protein. We show that DmCaBP1 is expressed in a specific spatiotemporal pattern during embryogenesis. In particular, it is expressed in midline precursor cells in the developing CNS. This is the first demonstration of tissue-specific expression for a member of this group of ER proteins and suggests a possible role for DmCABP1 as a molecular chaperone involved in nervous system development. The identification of the DmCaBP1 gene provides a basis for future genetic studies of its function.
Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.finkels@mail.med.upenn.edu.
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Li
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Musacchio
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Finkelstein
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D002490:Central Nervous System / Q000196:embryology / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004331:Drosophila melanogaster / Q000196:embryology / Q000201:enzymology*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000201:enzymology; D004742:Enhancer Elements, Genetic; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D019476:Insect Proteins / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009928:Organ Specificity; D017510:Protein Folding; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D019749:Sulfur-Sulfur Bond Isomerases / Q000096:biosynthesis* / Q000235:genetics
D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D019476:Insect Proteins; D009419:Nerve Tissue Proteins; C085577:Ca2+-binding protein-1; D019749:Sulfur-Sulfur Bond Isomerases