Dictyostelium discoideum protein disulfide isomerase, an endoplasmic reticulum resident enzyme lacking a KDEL-type retrieval signal.
The primary activity of protein disulfide isomerase (PDI), a multifunctional resident of the endoplasmic reticulum (ER), is the isomerization of disulfide bridges during protein folding. We isolated a cDNA encoding Dictyostelium discoideum PDI (Dd-PDI). Phylogenetic analyses and basic biochemical properties indicate that it belongs to a subfamily called P5, many members of which differ from the classical PDIs in many respects. They lack an intervening inactive thioredoxin module, a C-terminal acidic domain involved in Ca2+ binding and a KDEL-type retrieval signal. Despite the absence of this motif, the ER is the steady-state location of Dd-PDI, suggesting the existence of an alternative retention mechanism for P5-related enzymes.
Monnat
J
J
Department of Molecular Cell Research, Max-Planck-Institute for Medical Research, Heidelberg, Germany.
Hacker
U
U
Geissler
H
H
Rauchenberger
R
R
Neuhaus
E M
EM
Maniak
M
M
Soldati
T
T
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004023:Dictyostelium / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D008969:Molecular Sequence Data; D019704:Protein Disulfide-Isomerases / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017421:Sequence Analysis
D019704:Protein Disulfide-Isomerases