The ubiquitin-proteasome pathway protects Chlamydomonas reinhardtii against selenite toxicity, but is impaired as reactive oxygen species accumulate

被引:34
作者
Vallentine, Patrick [1 ]
Hung, Chiu-Yueh [2 ]
Xie, Jiahua [2 ]
Van Hoewyk, Doug [1 ]
机构
[1] Coastal Carolina Univ, Dept Biol, Conway, SC 29526 USA
[2] N Carolina Cent Univ, BRITE Inst, Dept Pharmaceut Sci, Durham, NC 27707 USA
基金
美国国家科学基金会;
关键词
Chlamydomonas; malformed selenoprotein; mitochondrial superoxide; proteasome; reactive oxygen species; selenium; ubiquitin; 26S PROTEASOME; OXIDATIVE STRESS; MALFORMED SELENOPROTEINS; QUALITY CONTROL; CELL-DEATH; SYSTEM; MECHANISMS; TOLERANCE; RESPONSES; SUBUNIT;
D O I
10.1093/aobpla/plu062
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
The ubiquitin-proteasome pathway (UPP) coordinates a myriad of physiological processes in higher plants, including abiotic stress responses, but it is less well characterized in algal species. In this study, the green alga Chlamydomonas reinhardtii was used to gain insights into the role of the UPP during moderate and severe selenite stress at three different time points. The data indicate that activity of the UPP in response to selenium (Se) stress was both time and dose dependent. Moderate selenite stress increased proteasome activity, protein ubiquitination and the proteasomal removal of malformed selenoproteins. However, severe Se stress caused by prolonged selenite treatment or high selenite concentration decreased proteasome activity, inhibited protein ubiquitination and prevented the proteasomal removal of selenoproteins. The UPP impairment during severe Se stress was associated with the observed accumulation of reactive oxygen species (ROS), including mitochondrial superoxide. Additionally, proteasomal inhibition decreased the concentration of chlorophyll in cultures challenged with Se. Therefore, although the UPP protects Chlamydomonas against Se stress, severe oxidative stress induced by selenite toxicity likely hinders the UPP's capacity to mediate a stress response. The possibility that stress tolerance in plants is dependent upon optimal UPP activity and maintenance is discussed.
引用
收藏
页数:11
相关论文
共 52 条
[1]   Reactive oxygen species: Metabolism, oxidative stress, and signal transduction [J].
Apel, K ;
Hirt, H .
ANNUAL REVIEW OF PLANT BIOLOGY, 2004, 55 :373-399
[2]   COPPER ENZYMES IN ISOLATED CHLOROPLASTS - POLYPHENOLOXIDASE IN BETA-VULGARIS [J].
ARNON, DI .
PLANT PHYSIOLOGY, 1949, 24 (01) :1-15
[3]   Production of reactive oxygen species, impairment of photosynthetic function and dynamic changes in mitochondria are early events in cadmium-induced cell death in Arabidopsis thaliana [J].
Bi, YuHua ;
Chen, WenLi ;
Zhang, WeiNa ;
Zhou, Quan ;
Yun, LiJuan ;
Xing, Da .
BIOLOGY OF THE CELL, 2009, 101 (11) :629-643
[4]  
BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3
[5]   SELENIUM - TOXICITY AND TOLERANCE IN HIGHER-PLANTS [J].
BROWN, TA ;
SHRIFT, A .
BIOLOGICAL REVIEWS, 1982, 57 (FEB) :59-84
[6]   Protein Quality Control in the Cytosol and the Endoplasmic Reticulum: Brothers in Arms [J].
Buchberger, Alexander ;
Bukau, Bernd ;
Sommer, Thomas .
MOLECULAR CELL, 2010, 40 (02) :238-252
[7]   Structure and functions of the 20S and 26S proteasomes [J].
Coux, O ;
Tanaka, K ;
Goldberg, AL .
ANNUAL REVIEW OF BIOCHEMISTRY, 1996, 65 :801-847
[8]   Alternative oxidase modulates leaf mitochondrial concentrations of superoxide and nitric oxide [J].
Cvetkovska, Marina ;
Vanlerberghe, Greg C. .
NEW PHYTOLOGIST, 2012, 195 (01) :32-39
[9]   Degradation of oxidized proteins by the 20S proteasome [J].
Davies, KJA .
BIOCHIMIE, 2001, 83 (3-4) :301-310
[10]   The balance between cell division and endoreplication depends on E2FC-DPB, transcription factors regulated by the ubiquitin-SCFSKP2A pathway in Arabidopsis [J].
del Pozo, Juan C. ;
Diaz-Trivino, Sara ;
Cisneros, Nerea ;
Gutierrez, Crisanto .
PLANT CELL, 2006, 18 (09) :2224-2235