iTRAQ-based quantitative proteomic analysis of Gloeothece sp. PCC 6909: Comparison with its sheathless mutant and adaptations to nitrate deficiency and sulfur limitation.

摘要: Gloeothece sp. PCC 6909 is a unicellular N(2)-fixing cyanobacterium with well defined and highly developed sheath surrounding its cells. A sheathless mutant of this strain was previously obtained by chemical mutagenesis and, although lacking the sheath, it releases large amounts polysaccharides into culture medium. To provide global understanding on metabolic differences between two phenotypes, proteomes wild type were analyzed using cross-species proteomics approach coupled iTRAQ isobaric tagging technology, since their genome sequences are not yet available. Effects arising from presence/absence nitrate sulfur presented as metabolically directed follow-up studies. These nutrients believed to play major role in Gloeothece's metabolism, including production extracellular polymeric substances - EPS. 454, 124, 53 proteins identified reliably quantified homology anchoring approaches for described. The results strongly suggest that affected regulation number key cellular processes, revealed significant fold changes observed covering spectrum functional groups. Moreover, they new insights adaptations cells nitrate-deficiency sulfur-limitation.