title: Time course of lead induced proteomic changes in gill of the Antarctic limpet Nacella Concinna (Gastropoda: Patellidae).
abstract: The effect of increasing levels of metals from anthropogenic sources on Antarctic invertebrates is poorly understood. Here we exposed limpets (Nacella concinna) to 0, 0.12 and 0.25 μg L− 1 lead for 12, 24, 48 and 168 h. We subsequently quantified the changes in protein abundance from gill, using 2D gel electrophoresis and mass spectrometry. We identified several antioxidant proteins, including the metal binding Mn-superoxide dismutase and ferritin, increasing abundances early on. Chaperones involved in the redox-dependent maturation of proteins in the endoplasmic reticulum (ER) showed higher abundance with lead at 48 h. Lead also increased the abundance of Zn-binding carbonic anhydrase at 12 h, suggesting a challenge to acid-base balance. Metabolic proteins increased abundance at 168 h, suggesting a greater ATP demand during prolonged exposure. Changes in abundance of the small G-protein cdc42, a signaling protein modifying cytoskeleton, increased early and subsequently reversed during prolonged exposure, possibly leading to the modification of thick filament structure and function. We hypothesize that the replacement of metals initially affected antioxidant proteins and increased the production of reactive oxygen species. This disrupted the redox-sensitive maturation of proteins in the ER and caused increased ATP demand later on, accompanied by changes in cytoskeleton.
  
  
  
  Proteomic analysis of gill tissue in Antarctic limpets exposed to different concentrations of lead (Pb) over a 168 h time period showed that proteomic changes vary with time. These changes included an increase in the demand of scavenging reactive oxygen species, acid-base balance and a challenge to protein homeostasis in the endoplasmic reticulum early on and subsequently an increase in energy metabolism, cellular signaling, and cytoskeletal modifications. Based on this time course, we hypothesize that the main mode of action of lead is a replacement of metal-cofactors of key enzymes involved in the scavenging of reactive oxygen species and the regulation of acid-base balance.
authors.affiliation: Universidade Federal do Paraná, Department of Cell Biology, Adaptive Biology Laboratory, Curitiba, Paraná, Brazil.
authors.forename: Cláudio Adriano
authors.initials: CA
authors.lastname: Piechnik
authors.affiliation: University of Innsbruck, Institute of Zoology, Technikerstraße 25, 6020 Innsbruck, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Höckner
authors.affiliation: Universidade Federal do Paraná, Department of Cell Biology, Adaptive Biology Laboratory, Curitiba, Paraná, Brazil.
authors.forename: Maria Rosa Dmengeon Pedreiro
authors.initials: MR
authors.lastname: de Souza
authors.affiliation: Universidade Federal do Paraná, Department of Cell Biology, Adaptive Biology Laboratory, Curitiba, Paraná, Brazil.
authors.forename: Lucélia
authors.initials: L
authors.lastname: Donatti
authors.affiliation: California Polytechnic State University, Department of Biological Sciences, Center for Coastal Marine Studies, Environmental Proteomics Laboratory, 1 Grand Ave., San Luis Obispo, CA 93407-0401, USA. Electronic address: ltomanek@calpoly.edu.
authors.forename: Lars
authors.initials: L
authors.lastname: Tomanek
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects; D000818:Animals; D000864:Antarctic Regions; D000975:Antioxidants; D049851:Gastropoda / Q000737:chemistry*; D005880:Gills; D007854:Lead / Q000633:toxicity*; D020543:Proteome / Q000032:analysis* / Q000187:drug effects; D040901:Proteomics; D017382:Reactive Oxygen Species; D013997:Time Factors
chemical_list: D000975:Antioxidants; D020543:Proteome; D017382:Reactive Oxygen Species; D007854:Lead
keywords: Acid-base balance; Antarctica; Cytoskeleton; Lead; Limpet; Oxidative stress; Protein homeostasis