Location: Cereal Crops ResearchTitle: Interacting protein partners of Arabidopsis RNA binding protein AtRBP45b Author
Submitted to: Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/29/2016
Publication Date: 1/20/2017
Citation: Muthuramalingam, M., Wang, Y., Li, Y., Mahalingam, R. 2017. Interacting protein partners of Arabidopsis RNA binding protein AtRBP45b. Plant Biology. 19:327-334. doi: 10.111/plb.12540. Interpretive Summary: Relatively very little is known about post-transcriptional gene regulation mediated by RNA binding proteins (RBPs) during stress. Identifying and determining the functions of key regulatory genes such as AtRBP45b involved in oxidative signaling will provide rational targets for engineering resistance to multiple stresses in plants and thus improve plant productivity. This will be a vital contribution for enhancing food security in the context of global climate change. The AtRBP45b protein has domains that indicate interactions with other proteins. In this study we have used a combination of biochemical pull-down assays, mass spectrometry, bioinformatics and yeast-two hybrid analysis to identify the proteins that interact with AtRBP45b. This knowledge has helped us to determine that AtRBP45b is involved in basic RNA metabolic processes such as mRNA stability and translation initiation.
Technical Abstract: RNA binding proteins (RBPs) are important players in post-transcriptional gene regulation and shown to play an important role in normal development and in response to environmental perturbations. Arabidopsis RBP, AtRBP45b with triple RNA recognition motifs (RRMs) have are closely related to the yeast CSX1 protein, a global regulator of oxidative signaling. In planta GFP-tagging indicated AtRBP45b is localized to the nucleus and the cytosol. AtRBP45b protein has a N-terminal Proline-rich region and a C-terminal Glutamine-rich domain that are usually involved in protein-protein interactions. A FLAG-tagged AtRBP45b under the control of 35S promoter in the atrbp45b-1 mutant background was used to pull down AtRBP45b interacting proteins. About 30 proteins were identified by mass spectrometry based analysis of the coimmunoprecipitated proteins. Using information from interactome databases, pull-down assays and localization data, we selected 12 putative interacting proteins for yeast-2-hybrid analysis. Cap binding protein and polyA binding protein were shown to interact with AtRBP45b. Furthermore, like many other RBPs, AtRBP45 is also likely to dimerize. Based on its interacting partners we speculate that AtRBP45b may play an important role in RNA metabolism, especially in aspects related to mRNA stability and translation initiation.