Comparative proteomics of temperate and polar Phaeocystis species
Mohapatra, Bidyut R.; Schambeau, Lindsay; Pannell, Lewis K.; Kiene, Ronald P.
Despite the importance of Phaeocystis species (Haptophyceae) in marine planktonic bloom dynamics, and biogeochemical cycling of carbon and sulfur in polar and temperate seas, the molecular basis of their ecophysiology remains poorly studied. In this paper, a comparative proteomics study was performed for the first time with actively growing cultures of two ubiquitous Phaeocystis species: temperate Phaeocystis jahnii strain CCMP 2496 and polar Phaeocystis antarctica strain CCMP 1871. The gel-free shotgun proteomics analysis resulted the identification of 187 and 215 proteins in P. jahnii and P. antarctica, respectively. More than 60% of the identified proteins in both algae belonged to four EuKaryotic Orthologous Functional Groups: "cellular process and signaling", "information storage and processing", "metabolism" and "poorly characterized". The functional annotation of the identified proteins was able to discern temperate P. jahnii and polar P. antarctica by showing species-specific participation in biological processes and molecular functions. These proteomics data are important not only in understanding the physiology of these widely-distributed planktonic algae, but also to link them into marine biogeochemical cycles.