Project description:The algal holobiont, which consists of algae and the bacteria living on it, has developed strategies to handle environmental stresses, such as changes in temperature. The green alga Ulva (Chlorophyta) is home to bacteria that help the algae grow and develop, from germlings to mature plants. These bacteria release chemicals like thallusin, N-acyl homoserine lactone, and ectoine, which support the health and growth of the algae. However, there is limited research on the metabolome of cold-adapted Ulva holobionts, especially those from hard-to-reach regions like Antarctica, and how they respond to environmental changes. In this study, we examine the metabolites found in Ulva and its associated bacteria from Antarctica (Potter Cove) using high-resolution mass spectrometry. We identified small polar and zwitterionic metabolites, such as cysteinolic acid, ectoine, glutamine, glycerol, and proline, in the surface tissues of the algae with MALDI-MS. By profiling these metabolites using UHPLC-HRMS and ZIC-HILIC chromatography, we found that their levels change significantly in response to heat-stressed Antarctic Ulva holobionts. Our results suggest that environmental change can affect the interaction between seaweeds and their microbes by altering the metabolites involved in their chemical exchanges.
The Data contains the Ulva metabolome profiles (.mzXML) analyzed using ZIC-HILIC chromatography coupled with HRMS (QExactive). Acquisition was conducted with the polarity switch mode and ddMS acquisition was done on the QC pool samples. The Metadata, normalization factor and results files from CD 3.3 can be found in the supplementary files.
Project description:Wu C, Tatavarty V, Jean-Beltran PM, Guerrero A, Keshishian H, Krug K, MacMullan M, de Arce KP, Carr SA, Cottrell J, Turrigiano GG. 2021
Homeostatic synaptic plasticity requires widespread remodeling of synaptic signaling and scaffolding networks, but the role of posttranslational modifications in this process has not been systematically studied. Here we analyzed changes in the phosphoproteome during synaptic scaling up and down and found wide-spread and temporally complex changes. These included 424 bidirectionally modulated phosphosites that were strongly enrichment for synapse-associated proteins, including the ASD-associated synaptic scaffold protein Shank3. Shank3 was dephosphorylated at two highly conserved sites (rat S1586 and S1615) during scaling up, and hyperphosphorylated during scaling down. These changes modified the synaptic localization of Shank3 during scaling, and phosphomimetic or deficient mutants of Shank3 prevented scaling up or down, respectively. Finally, we found that dephosphorylation of these sites via PP2A activity was essential for the maintenance of synaptic scaling up. Thus Shank3 undergoes an activity-dependent switch between hypo- and hyperphosphorylation at S1586/ S1615, that is necessary to enable scaling up or down, respectively. More broadly, our data suggest that widespread and bidirectional changes in the synaptic phosphoproteome are essential for the functional reconfiguration of synaptic scaffolds during homeostatic plasticity.
