Oxidative Stress Posttranslationally Regulates the Expression of Ha-Ras and Ki-Ras in Cultured Astrocytes
Joint Authors
Frati, Luigi
Messina, Samantha
Porcellini, Antonio
Source
Oxidative Medicine and Cellular Longevity
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-8, 8 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-10-31
Country of Publication
Egypt
No. of Pages
8
Main Subjects
Natural & Life Sciences (Multidisciplinary)
Biology
Abstract EN
Addition of hydrogen peroxide to cultured astrocytes induced a rapid and transient increase in the expression of Ha-Ras and Ki-Ras.
Pull-down experiments with the GTP-Ras-binding domain of Raf-1 showed that oxidative stress substantially increased the activation of Ha-Ras, whereas a putative farnesylated activated form of Ki-Ras was only slightly increased.
The increase in both Ha-Ras and Ki-Ras was insensitive to the protein synthesis inhibitor, cycloheximide, and was occluded by the proteasomal inhibitor, MG-132.
In addition, exposure to hydrogen peroxide reduced the levels of ubiquitinated Ras protein, indicating that oxidative stress leads to a reduced degradation of both isoforms through the ubiquitin/proteasome pathway.
Indeed, the late reduction in Ha-Ras and Ki-Ras was due to a recovery of proteasomal degradation because it was sensitive to MG-132.
The late reduction of Ha-Ras levels was abrogated by compound PD98059, which inhibits the MAP kinase pathway, whereas the late reduction of Ki-Ras was unaffected by PD98059.
We conclude that oxidative stress differentially regulates the expression of Ha-Ras and Ki-Ras in cultured astrocytes, and that activation of the MAP kinase pathway by oxidative stress itself or by additional factors may act as a fail-safe mechanism limiting a sustained expression of the potentially detrimental Ha-Ras.
American Psychological Association (APA)
Messina, Samantha& Frati, Luigi& Porcellini, Antonio. 2012. Oxidative Stress Posttranslationally Regulates the Expression of Ha-Ras and Ki-Ras in Cultured Astrocytes. Oxidative Medicine and Cellular Longevity،Vol. 2012, no. 2012, pp.1-8.
https://search.emarefa.net/detail/BIM-498511
Modern Language Association (MLA)
Messina, Samantha…[et al.]. Oxidative Stress Posttranslationally Regulates the Expression of Ha-Ras and Ki-Ras in Cultured Astrocytes. Oxidative Medicine and Cellular Longevity No. 2012 (2012), pp.1-8.
https://search.emarefa.net/detail/BIM-498511
American Medical Association (AMA)
Messina, Samantha& Frati, Luigi& Porcellini, Antonio. Oxidative Stress Posttranslationally Regulates the Expression of Ha-Ras and Ki-Ras in Cultured Astrocytes. Oxidative Medicine and Cellular Longevity. 2012. Vol. 2012, no. 2012, pp.1-8.
https://search.emarefa.net/detail/BIM-498511
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-498511