In silico prediction of the secretome from the invasive neurotoxic marine dinoflagellate Alexandrium catenella

Abstract

Summary Alexandrium catenella, a marine dinoflagellate responsible for harmful algal blooms (HABs), proliferates with greater frequency, distribution and intensity, in disturbed marine coastal ecosystems. The proteins secreted into seawater may play a crucial role in maintaining this dinoflagellate in these ecosystems, but this possibility has never been investigated before. In this study, the A. catenella secretome was predicted from its transcriptome by combining several bioinformatics tools. Our results predict a secretome of 2 779 proteins, among which 79% contain less than 500 amino acids, suggesting that most secreted proteins are short in length. The predicted secretome includes 963 proteins (35%) with Pfam domains: 773 proteins with one Pfam domain and 190 proteins with two or more Pfam domains. Their functional annotation showed that they are mainly involved in (i) proteolysis, (ii) stress responses and (iii) primary metabolism. In addition, 47% of the secreted proteins appear to be enzymes, primarily peptidases, known to be biologically active in the extracellular medium during stress responses. Finally, this study provides a wealth of candidates of proteins secreted by A. catenella, which may interact with the marine environment and help this dinoflagellate develop in various environmental conditions.

Metal stresses modify soluble proteomes and toxin profiles in two Mediterranean strains of the distributed dinoflagellate Alexandrium pacificum

“…However, few studies have investigated the ability of A. pacificum to adapt to and/or tolerate disturbed environments such as metal-contaminated coastal ecosystems. In silico prediction of the A. pacificum secretome, outside specific conditions, has shown that proteins released in the extracellular medium are J o u r n a l P r e -p r o o f mainly enzymes (Chetouhi et al, 2019). Enzymatic activity of these secreted proteins could contribute to regulate the extracellular environment and be involved in some stress responses, which may help this dinoflagellate to develop in metal-contaminated conditions.…”

Intraspecific variability in membrane proteome, cell growth, and morphometry of the invasive marine neurotoxic dinoflagellate Alexandrium pacificum grown in metal-contaminated conditions

“…An ecotoxicoproteomic study on the Mediterranean strain (ACT03) of A. pacificum showed that single-stress by lead or zinc induced the down-regulation of many proteins constituting its soluble proteome, compensated by the up-regulation of some proteins like ATP-synthase able to contribute to an adaptive proteomic response in metal-contaminated ecosystems (Jean et al, 2017). Using an in silico approach, the secretome of A. pacificum has been predicted, showing that 47% of the secreted proteins are enzymes (peptidases) active in the extracellular medium during stress responses, Journal Pre-proof J o u r n a l P r e -p r o o f 5 which could help this dinoflagellate to develop in various environmental conditions, such as in metal-contaminated areas (Chetouhi et al, 2019).…”