NUCB1, the Drosophila melanogaster homolog of the mammalian EF-hand proteins NEFA and nucleobindin.
Mammalian NEFA and nucleobindin are calcium-binding proteins containing a signal peptide, two EF-hand motifs, acidic and basic regions and a leucine-zipper motif. Although they have been discussed to be involved in autoimmunity, apoptosis and calcium homeostasis in the Golgi apparatus and bone matrix, their exact role remains unknown. Here we report the cloning of their Drosophila homolog, nucb1, as well as the analysis of its expression pattern during embryogenesis and the subcellular localization of the NUCB1 protein. The nucb1 mRNA and the NUCB1 protein were found to be expressed maternally and zygotically, and they accumulate ubiquitously at low levels during all embryonic stages due to a maternal component. From stage 11 onward, high levels of zygotic expression can be detected specifically in the salivary glands and their placodes. In contrast to the known mammalian family members, the NUCB1 protein localizes in a subpattern of cytoplasmic substructures, probably the Golgi apparatus.
Otte
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S
Max-Planck-Institut für experimentelle Medizin, Abteilung Immunchemie, Hermann-Rein-Strasse 3, D-37075, Göttingen, Germany. sotte@gwdg.de
Barnikol-Watanabe
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S
Vorbrüggen
G
G
Hilschmann
N
N
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D006133:Growth Substances / Q000235:genetics; D008322:Mammals; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions
D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006133:Growth Substances; C121963:NUCB1 protein, Drosophila; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins