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Molecular cloning and characterization of soybean protein disulfide isomerase family proteins with nonclassic active center motifs
Author(s) -
Iwasaki Kensuke,
Kamauchi Shinya,
Wadahama Hiroyuki,
Ishimoto Masao,
Kawada Teruo,
Urade Reiko
Publication year - 2009
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2009.07123.x
Subject(s) - protein disulfide isomerase , biochemistry , biology , endoplasmic reticulum , complementary dna , protein family , gene family , gene , microbiology and biotechnology , genome
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. Structured digital abstract• MINT‐7137566 : Bip (uniprotkb: Q587K1 ), GmPDIL‐3b (genbank_nucleotide_g: 51848586 ) and GmPDIL‐3a (genbank_nucleotide_g: 51848584 ) colocalize ( MI:0403 ) by cosedimentation through density gradients ( MI:0029 )