title: Molecular cloning and characterization of soybean protein disulfide isomerase family proteins with nonclassic active center motifs.
abstract: Protein disulfide isomerase (PDI) and other PDI family proteins are members of the thioredoxin superfamily and are thought to play important roles in disulfide bond formation and isomerization in the endoplasmic reticulum (ER). The exact functions of PDI family proteins in plants remain unknown. In this study, we cloned two novel PDI family genes from soybean leaf (Glycine max L. Merrill cv. Jack). The cDNAs encode proteins of 520 and 523 amino acids, and have been denoted GmPDIL-3a and GmPDIL-3b, respectively. GmPDIL-3a and GmPDIL-3b are the first plant ER PDI family proteins reported to contain the nonclassic redox center motif CXXS/C, and both proteins are ubiquitously expressed in the plant body. However, recombinant GmPDIL-3a and GmPDIL-3b did not function as oxidoreductases or as molecular chaperones in vitro, although a proportion of each protein formed complexes in both thiol-dependent and thiol-independent ways in the ER. Expression of GmPDIL-3a and GmPDIL-3b in the cotyledon increased during seed maturation when synthesis of storage proteins was initiated. These results suggest that GmPDIL-3a and GmPDIL-3b may play important roles in the maturation of the cotyledon by mechanisms distinct from those of other PDI family proteins.
authors: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan.
authors: Kensuke
authors: K
authors: Iwasaki
authors: Shinya
authors: S
authors: Kamauchi
authors: Hiroyuki
authors: H
authors: Wadahama
authors: Masao
authors: M
authors: Ishimoto
authors: Teruo
authors: T
authors: Kawada
authors: Reiko
authors: R
authors: Urade
mesh_terms: D020134:Catalytic Domain; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D017931:DNA Primers; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D007700:Kinetics; D018515:Plant Leaves / Q000201:enzymology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology* / Q000235:genetics*
chemical_list: D003062:Codon; D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D018749:RNA, Plant; D011994:Recombinant Proteins; D019704:Protein Disulfide-Isomerases