Naslov
Ras-like small GTPases form a large family of proteins in the marine sponge Suberites domuncula

Autori
Ćetković, Helena ; Mikoč, Andreja ; Müller, Werner E. G. ; Gamulin, Vera

Izvornik
Journal of Molecular Evolution (0022-2844) 64 (2007), 3; 332-341

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Porifera; Rab proteins; evolution of Metazoa

Sažetak
Sponges (Porifera) are the simplest and the most ancient metazoan animals, which branched of first from the common ancestor of all multicellular animals. We have inspected ~13000 partial cDNA sequences (ESTs) from the marine sponge Suberites domuncula and have identified full or partial cDNA sequences coding for ~50 different Ras-like small GTPases. 44 sponge proteins from the Ras family are described here: 6 proteins from Ras subfamily, 5 from Rho, 6 from Arf, 1 Ran and 26 Rabs or Rab-like proteins. Isoforms of the same protein were not detected ; the most closely related proteins are 2 Rho proteins with 74% identity. Small GTPases from sponge display higher degree of sequence conservation with orthologs from vertebrates (53-93% identity) than with those from either Caenorhabditis elegans or Drosophila melanogaster. The real number of small GTPases in this sponge is certainly much higher than 50, because the actual S. domuncula database of ~13000 ESTs contains at most 3000 non-redundant cDNA sequences. Number of genes for Ras-like small GTPases in yeast, C. elegans, D. melanogaster and humans is 30, 56, 90 and 174, respectively. Both model invertebrates have only 29 Rabs or Rab-like proteins, compared with 26 already found in sponge, and are missing at least one Rab (Rab24) present in S. domuncula and mammals. Our results indicate that duplications and diversifications of genes encoding Ras-like small GTPases, and especially Rab subfamily of small GTPases, happened very early in the evolution of Metazoa.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA