Taxonomic distribution of proteins containing NOSIC domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing NOSIC domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Insights into the evolution of the nucleolus by an analysis of its proteindomain repertoire.

Staub E, Fiziev P, Rosenthal A, Hinzmann B
Bioessays. 2004; 26: 567-81

Recently, the first investigation of nucleoli using mass spectrometry ledto the identification of 271 proteins. This represents a rich resource fora comprehensive investigation of nucleolus evolution. We applied aprotocol for the identification of known and novel conserved proteindomains of the nucleolus, resulting in the identification of 115 known and91 novel domain profiles. The phyletic distribution of nucleolar proteindomains in a collection of complete proteomes of selected organisms fromall domains of life confirms the archaebacterial origin of the coremachinery for ribosome maturation and assembly, but also revealssubstantial eubacterial and eukaryotic contributions to nucleolusevolution. We predict that, in different phases of nucleolus evolution,protein domains with different biochemical functions were recruited to thenucleolus. We suggest a model for the late and continuous evolution of thenucleolus in early eukaryotes and argue against an endosymbiotic origin ofthe nucleolus and the nucleus. Supplementary material for this article canbe found on the BioEssays website athttp://www.interscience.wiley.com/jpages/0265-9247/suppmat/index.html.