Dataset Information

Expanding the Family of Extracellular Chaperones: Identification of Plasma Proteins with Chaperone Activity

ABSTRACT: Proteostasis, the balance of protein synthesis, folding and degradation, is essential to maintain cellular function and viability, and the many known intracellular chaperones are recognised as playing key roles in sustaining life. In contrast, the identity of constitutively secreted extracellular chaperones (ECs) and their physiological roles in extracellular proteostasis is less completely understood. In the current study we designed and implemented a novel strategy to discover new ECs present in human blood. This strategy was based on the well-known propensity of chaperones to bind to regions of hydrophobicity exposed on misfolding proteins. We attached a destabilised protein that misfolds at 37 oC to magnetic beads, and used this as "bait" to bind to potential EC proteins. The bait-bearing beads were incubated in human serum for 2 h at either 37 oC or 4 oC (the latter serving as a control, not expected to induce bait protein misfolding). Proteins eluted from the beads were analysed by mass spectrometry to identify individual proteins and their relative abundance in eluates from beads incubated at 37 oC versus 4 oC. A group of proteins significantly more abundant in the eluate from the beads incubated at 37 oC were selected for in vitro analysis of chaperone activity. It was shown that vitronectin and plasminogen activator-3 inhibited both the in vitro aggregation of the Alzheimer's peptide (Aβ1-42) to form fibrillar amyloid, and the aggregation of citrate synthase to form unstructured (amorphous) aggregates. In contrast, prothrombin, C1r, and C1s inhibited the aggregation of Aβ1-42 but did not inhibit citrate synthase aggregation. This study thus identified five novel and abundant putative ECs which may play important roles in the maintenance of extracellular proteostasis, and which apparently have differing abilities to inhibit the amorphous and amyloid-forming protein aggregation pathways.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood Plasma

SUBMITTER: Albert Lee

LAB HEAD: Mark Wilson

PROVIDER: PXD027042 | Pride | 2021-09-24

REPOSITORIES: Pride

ACCESS DATA

Publications

Expanding the family of extracellular chaperones: Identification of human plasma proteins with chaperone activity.

Geraghty Nicholas J NJ Satapathy Sandeep S Kelly Megan M Cheng Flora F Lee Albert A Wilson Mark R MR

Protein science : a publication of the Protein Society 20211004 11

Proteostasis, the balance of protein synthesis, folding and degradation, is essential to maintain cellular function and viability, and the many known intracellular chaperones are recognized as playing key roles in sustaining life. In contrast, the identity of constitutively secreted extracellular chaperones (ECs) and their physiological roles in extracellular proteostasis is less completely understood. We designed and implemented a novel strategy, based on the well-known propensity of chaperones ...[more]

PMID: 34553437

Similar Datasets

Project description:Major depressive disorder (MDD) is the psychiatric disorder with the highest prevalence in the world. Pharmacological antidepressant treatment (AD), such as selective serotonin reuptake inhibitors [SSRI, i.e. fluoxetine (Flx)] is the first line of treatment for MDD. Despite its efficacy, lack of AD response occurs in numerous patients characterizing Difficult-to-treat Depression. ElectroConvulsive Therapy (ECT) is a highly effective treatment inducing rapid improvement in depressive symptoms and high remission rates of ~50–63% in patients with pharmaco-resistant depression. Nevertheless, the need to develop reliable treatment response predictors to guide personalized AD strategies and supplement clinical observation is becoming a pressing clinical objective. Here, we propose to establish a proteomic peripheral biomarkers signature of ECT response in an anxio/depressive animal model of non-response to AD. Using an emotionality score based on the analysis complementary behavioral tests of anxiety/depression (Elevated Plus Maze, Novelty Suppressed Feeding, Splash Test), we showed that a 4-week corticosterone treatment (35 μg/ml, Cort model) in C57BL/6JRj male mice induced an anxiety/depressive-like behavior. A 28-days chronic fluoxetine treatment (Flx, 18 mg/kg/day) reduced corticosterone-induced increase in emotional behavior. A 50% decrease in emotionality score threshold before and after Flx, was used to separate Flx-responding mice (Flx-R, n=18), or Flx non-responder mice (Flx-NR, n=7). Then, Flx-NR mice received 7 sessions of electroconvulsive seizure (ECS, equivalent to ECT in humans) and blood was collected before and after ECS treatment. Chronic ECS normalized the elevated emotionality observed in Flx-NR mice. Then, proteins were extracted from peripheral blood mononuclear cells (PBMCs) and isolated for proteomic analysis using a high-resolution MS Orbitrap. The proteomic analysis revealed a signature of 33 peripheral proteins associated with response to ECS (7 down- and 26 upregulated). These proteins were previously associated with mental disorders and involved in regulating pathways which participate to the depressive disorder etiology. remark for sample name : ECTR=Flx-NR-ES, C=cort/Veh, CFNR= Flx-NR

Dataset Information

Expanding the Family of Extracellular Chaperones: Identification of Plasma Proteins with Chaperone Activity

Publications

Expanding the family of extracellular chaperones: Identification of human plasma proteins with chaperone activity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure