title: Crystal structure and functional analysis of Drosophila Wind, a protein-disulfide isomerase-related protein.
abstract: In the developing Drosophila melanogaster embryo, dorsal-ventral patterning displays an absolute requirement for the product of the essential windbeutel gene, Wind. In homozygous windbeutel mutant flies, dorsal-ventral patterning fails to initiate because of the failure of the Golgi-resident proteoglycan-modifying protein, Pipe, to exit the endoplasmic reticulum, and this leads to the death of the embryo. Here, we describe the three-dimensional structure of Wind at 1.9-A resolution and identify a candidate surface for interaction with Pipe. This represents the first crystal structure of a eukaryotic protein-disulfide isomerase-related protein of the endoplasmic reticulum to be described. The dimeric protein is composed of an N-terminal thioredoxin domain and a C-terminal alpha-helical domain unique to protein-disulfide isomerase D proteins. Although Wind carries a CXXC motif that is partially surface accessible, this motif is redox inactive, and the cysteines are not required for the targeting of Pipe to the Golgi. However, both domains are required for targeting Pipe to the Golgi, and, although the mouse homologue ERp28 cannot replace the function of Wind, exchange of the Wind D-domain with that of ERp28 allows for efficient Golgi transport of Pipe.
authors.affiliation: Department of Structural Chemistry, University of Göttingen, Tammanstrasse 4, Germany.
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Ma
authors.forename: Chaoshe
authors.initials: C
authors.lastname: Guo
authors.forename: Kathrin
authors.initials: K
authors.lastname: Barnewitz
authors.forename: George M
authors.initials: GM
authors.lastname: Sheldrick
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Soling
authors.forename: Isabel
authors.initials: I
authors.lastname: Uson
authors.forename: David M
authors.initials: DM
authors.lastname: Ferrari
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000737:chemistry* / Q000196:embryology / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D009154:Mutation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D015238:Sulfotransferases / Q000378:metabolism; D013879:Thioredoxins / Q000737:chemistry; D014162:Transfection
chemical_list: D029721:Drosophila Proteins; D011994:Recombinant Proteins; C110185:wbl protein, Drosophila; D013879:Thioredoxins; D015238:Sulfotransferases; C115847:pip protein, Drosophila