Small GTPases and the evolution of the eukaryotic cell.
The origin of eukaryotes is one of the major challenges of evolutionary cell biology. Other than the endosymbiotic origin of mitochondria and chloroplasts, the steps leading to eukaryotic endomembranes and endoskeleton are poorly understood. Ras-family small GTPases are key regulators of cytoskeleton dynamics, vesicular trafficking and nuclear function. They are specific for eukaryotes and their expansion probably traces the evolution of core eukaryote features. The phylogeny of small GTPases suggests that the first endomembranes to evolve during eukaryote evolution had secretory, and not phagocytic, function. Based on the reconstruction of putative roles for ancestral small GTPases, a hypothetical scenario on the origins of the first endomembranes, the nucleus, and phagocytosis is presented.
Jékely
Gáspár
G
European Molecular Biology Laboratory, Developmental Biology, Meyerhofstrasse 1., 69117 Heidelberg, Germany. jekely@enzim.hu
D000818:Animals; D005075:Biological Evolution; D002467:Cell Nucleus; D005057:Eukaryotic Cells / Q000166:cytology / Q000502:physiology*; D020558:GTP Phosphohydrolases / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008938:Mitosis; D008969:Molecular Sequence Data; D010587:Phagocytosis; D010802:Phylogeny; D018631:ras Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism
D020558:GTP Phosphohydrolases; D018631:ras Proteins