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Phosphorylation and concomitant structural changes in human 2‐Cys peroxiredoxin isotype I differentially regulate its peroxidase and molecular chaperone functions
Author(s) -
Jang Ho Hee,
Kim Sun Young,
Park Soo Kwon,
Jeon Hye Sook,
Lee Young Mee,
Jung Ji Hyun,
Lee Sun Yong,
Chae Ho Byoung,
Jung Young Jun,
Lee Kyun Oh,
Lim Chae Oh,
Chung Woo Sik,
Bahk Jeong Dong,
Yun Dae-Jin,
Cho Moo Je,
Lee Sang Yeol
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.12.030
Subject(s) - phosphorylation , chaperone (clinical) , peroxiredoxin , biochemistry , peroxidase , protein phosphorylation , chemistry , protein structure , biology , microbiology and biotechnology , enzyme , protein kinase a , medicine , pathology
The H 2 O 2 ‐catabolizing peroxidase activity of human peroxiredoxin I (hPrxI) was previously shown to be regulated by phosphorylation of Thr 90 . Here, we show that hPrxI forms multiple oligomers with distinct secondary structures. HPrxI is a dual function protein, since it can behave either as a peroxidase or as a molecular chaperone. The effects of phosphorylation of hPrxI on its protein structure and dual functions were determined using site‐directed mutagenesis, in which the phosphorylation site was substituted with aspartate to mimic the phosphorylated status of the protein (T90D‐hPrxI). Phosphorylation of the protein induces significant changes in its protein structure from low molecular weight (MW) protein species to high MW protein complexes as well as its dual functions. In contrast to the wild type (WT)‐ and T90A‐hPrxI, the T90D‐hPrxI exhibited a markedly reduced peroxidase activity, but showed about sixfold higher chaperone activity than WT‐hPrxI.