Heat shock causes destabilization of specific mRNAs and destruction of endoplasmic reticulum in barley aleurone cells.
AUTOR(ES)
Belanger, F C
RESUMO
In response to a phytohormone, gibberellic acid, the aleurone layers of barley seeds synthesize and secrete alpha-amylases, which are coded by a set of stable mRNAs. When aleurone layers are subjected to heat shock treatment, the synthesis of alpha-amylase is suppressed while heat shock proteins are induced. The suppression of alpha-amylase synthesis is not the result of translational control as reported in several other systems. Rather, the sequences of alpha-amylase mRNA are rapidly degraded during heat shock as shown by in vitro translation and dot blot hybridization with a cDNA probe. Upon recovery from heat shock, the tissue resumes the synthesis of alpha-amylase in 2-4 hr. However, in the presence of a transcription inhibitor, cordycepin, the resumption of synthesis of alpha-amylase does not take place, indicating that new transcription of alpha-amylase genes is necessary for this recovery process. The degradation of alpha-amylase mRNAs correlates with the rapid destruction of endoplasmic reticulum as observed by electron microscopy, a phenomenon that has not been reported previously as a heat shock response. Since alpha-amylase mRNA is associated with the endoplasmic reticulum via membrane-bound polyribosomes, we suggest that the destruction of the endoplasmic reticulum during heat shock causes the destabilization and the eventual degradation of alpha-amylase mRNA.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=323074Documentos Relacionados
- Effect of Gibberellin and Heat Shock on the Lipid Composition of Endoplasmic Reticulum in Barley Aleurone Layers.
- Hormone-Controlled Synthesis of Endoplasmic Reticulum in Barley Aleurone Cells
- Induced heat shock mRNAs escape the nucleocytoplasmic transport block in adenovirus-infected HeLa cells.
- Growth-related changes in specific mRNAs of cultured mouse cells.
- Cytokinin-induced mRNAs in cultured soybean cells.