20 research outputs found
Identifying Molecular Functions of Heliotropic Motor Tissue Through Proteomic Analysis of Soybean Pulvini
Heliotropic and nyctinastic leaf movement are mediated in soybean through turgor changes in the motor cells of the pulvinus, located at the base of the leaves. While some elements of the signaling pathways have been studied, a broad-scale protein identification has not yet been reported. In my research pulvini proteins were extracted in light- and dark-harvested soybean using the TCA/acetone method and identified by LC-MS/MS. Gene ontology analysis revealed proteins involved in proton transport were enriched in the soybean pulvinus proteome compared to a background soybean proteome. Proteins more highly expressed in the light were mostly stress response proteins, while under-expressed proteins were categorized as energy proteins. Further investigations using more sensitive extraction protocols and a multitude of sample times will build on these initial results to provide a thorough examination of heliotropic mechanisms at the molecular level
Differentially Expressed Proteins of Soybean (Glycine max) Pulvinus in Light and Dark Conditions
Some plant species both track and avoid the sun through turgor changes of the pulvinus tissue at the base of their leaves, maximizing light reception in dim conditions and minimizing cellular damage due to excessive light. Pulvinar response is known to be affected by both diurnally varying environmental factors and circadian patterns. Differential expression of the proteins between light and darkness are not well-known. In this study we used two-dimensional gel electrophoresis and mass spectrometry to separate and identify proteins in the soybean leaf pulvinus that were differentially expressed in the light compared to a dark control. Out of 165 protein spots previously identified (data not shown) 11 were found to have decreased expression in the light and 7 had increased light expression. The proteins that were more highly expressed in the light were mostly stress response proteins, while the under-expressed proteins were categorized as energy proteins. While the higher levels of expression of stress response proteins in the light align with other studies, the under-expressed light proteins require further examination to rule out artefactual results. These findings can provide a better understanding of the circadian pattern of protein expression in the legume pulvinus proteome
Proteomic analysis of the pulvinus, a heliotropic tissue, in Glycine max
Certain plant species respond to light, dark, and other environmental factors by leaf movement. Leguminous plants both track and avoid the sun through turgor changes of the pulvinus tissue at the base of leaves. Mechanisms leading to pulvinar turgor flux, particularly knowledge of the proteins involved, are not well-known. In this study we used two-dimensional gel electrophoresis and liquid chromatography-tandom mass spectrometry to separate and identify the proteins located in the soybean pulvinus. A total of 183 spots were separated and 195 proteins from 165 spots were identified and functionally analyzed using single enrichment analysis for gene ontology terms. The most significant terms were related to proton transport. Comparison with guard cell proteomes revealed similar significant processes but a greater number of pulvinus proteins are required for comparable analysis. To our knowledge, this is a novel report on the analysis of proteins found in soybean pulvinus. These findings provide a better understanding of the proteins required for turgor change in the pulvinus
ZAPS is a potent stimulator of signaling mediated by the RNA helicase RIG-I during antiviral responses
The poly(ADP-ribose) polymerases (PARPs) participate in various processes. Here, we report that the PARP-13/ZAP shorter isoform (hereafter called ZAPS), rather than the full length protein, is selectively induced by 3pRNA, and functions as a potent stimulator of retinoic acid-inducible gene-I (RIG-I)-mediated interferon (IFN) responses in human cells. ZAPS associates with RIG-I to promote the oligomerization and ATPase activity of RIG-I, leading to robust activation of IRF3 and NF-κB pathways. Disruption of the PARP-13/ZAP gene, ZC3HAV1, severely abrogated the induction of IFN-α, IFN-β and other cytokines upon viral infection. These results indicate that ZAPS is a key regulator of RIG-I signaling during the innate antiviral immune response, suggesting its possible use as a therapeutic target for viral control