title: Proteomic analysis of chromate-induced modifications in Pseudokirchneriella subcapitata.
abstract: In this work, we have analyzed the changes in the protein expression profile elicited by chromium (Cr) exposure in the freshwater green alga Pseudokirchneriella subcapitata, a well known bio-indicator of water pollution. We tested two experimental conditions, namely 0.2 and 1ppm of potassium dichromate; this concentration range includes the environmentally-relevant concentrations. Results show that neither concentration of potassium dichromate tested inhibited algal growth. However, the proteomic approach allowed the identification of relevant modifications in protein expression. In fact, among 800 protein spots detected by two-dimensional electrophoresis, 16 Cr-regulated proteins, including predicted and novel ones, were identified using tandem mass spectromic protein analysis. The results demonstrate a Cr-specific action in altering several photosynthetic proteins, such as ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), RuBisCO activase, Light Harvesting Chla/b protein complex, and stress related Chla/b binding protein1. Although Cr toxicity with respect to photosynthesis has been already documented, here we have identified, for the first time, the target proteins of this toxicity. Cr also induced a modulation of some proteins involved in the metabolism of the amino acids glutamine, arginine and methionine. These data are supported by changes in cellular polyamine (PA) accumulation. Present findings provide new insight into the molecular mechanisms underlying Cr toxicity in P. subcapitata.
authors: Dipartimento Ambiente, Salute, Sicurezza, Università degli Studi dell'Insubria, via G.B. Vico 46, Varese, Italy.
authors: Candida
authors: C
authors: Vannini
authors: Milena
authors: M
authors: Marsoni
authors: Guido
authors: G
authors: Domingo
authors: Fabiana
authors: F
authors: Antognoni
authors: Stefania
authors: S
authors: Biondi
authors: Marcella
authors: M
authors: Bracale
mesh_terms: D020418:Algal Proteins / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism; D000460:Chlorophyta / Q000254:growth & development / Q000378:metabolism*; D002840:Chromates / Q000633:toxicity*; D015180:Electrophoresis, Gel, Two-Dimensional; D005618:Fresh Water; D010788:Photosynthesis / Q000187:drug effects; D010858:Pigmentation / Q000187:drug effects; D040901:Proteomics; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D020418:Algal Proteins; D000596:Amino Acids; D002840:Chromates; D014874:Water Pollutants, Chemical