Profound redox sensitivity of peptidyl-prolyl isomerase activity in Arabidopsis thylakoid lumen.
Proteomic, enzymatic, and mutant analyses revealed that peptidyl-prolyl isomerase (PPIase) activity in the chloroplast thylakoid lumen of Arabidopsis is determined by two immunophilins: AtCYP20-2 and AtFKBP13. These two enzymes are responsible for PPIase activity in both soluble and membrane-associated fractions of thylakoid lumen suggesting that other lumenal immunophilins are not active towards the peptide substrates. In thiol-reducing conditions PPIase activity of the isolated AtFKBP13 and of the total thylakoid lumen is suppressed several fold. Profound redox-dependence of PPIase activity implies oxidative activation of protein folding catalysis under oxidative stress and photosynthetic oxygen production in the thylakoid lumen of plant chloroplasts.
Shapiguzov
Alexey
A
Division of Cell Biology, Linköping University, SE-581 85 Linköping, Sweden.
Edvardsson
Anna
A
Vener
Alexander V
AV
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D021983:Cyclophilins / Q000737:chemistry / Q000378:metabolism; D020104:Immunophilins / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D022021:Tacrolimus Binding Proteins / Q000737:chemistry / Q000378:metabolism; D020524:Thylakoids / Q000201:enzymology*
D021983:Cyclophilins; D022021:Tacrolimus Binding Proteins; D020104:Immunophilins; D019696:Peptidylprolyl Isomerase