Change of carbon source causes dramatic effects in the phospho-proteome of the Archaeon Sulfolobus solfataricus

Dominik Esser, Khoa Trong Pham, Julia Reimann, Sonja-Verena Albers, Bettina Siebers and Phillip Craig Wright (2012) [PubMed]


Protein phosphorylation, is known to occur in Archaea. However, knowledge of phosphorylation in the third domain of life is rather scarce. Homology based searches of archaeal genome sequences reveals the absence of two component systems in crenarchaeal genomes, but the presence of eukaryotic like protein kinases and protein phosphatases. Here, the influence of the offered carbon source (glucose versus tryptone) on the phospho-proteome of Sulfolobus solfataricus P2 was studied by PAcIFIC (precursor acquisition independent from ion count). In comparison to previous phospho-proteome studies, a high number of phosphorylation sites (1318) located on 690 phospho-peptides from 540 unique phospho-proteins were detected. Thus increasing the number of currently known archaeal phospho-proteins from 80 to 621. Furthermore, a 25.8/20.6/53.6 Ser/Thr/Tyr percentage ratio with an unexpectedly high predominance of tyrosine phosphorylation was detected. Phospho-proteins in most functional classes (21 out of 26 arCOGs) were identified, suggesting an important regulatory role in S. solfataricus. Focused on the central carbohydrate metabolism in response to the offered carbon source, tremendous changes were observed. The observed complex phosphorylation pattern suggests an important physiological function of protein phosphorylation in control of the central carbohydrate metabolism, which seems to particularly operate in channeling carbon flux into the respective metabolic pathways.