Unexpected roles of a Dictyostelium homologue of eukaryotic EF-2 in growth and differentiation.
EF-2 is believed to be indispensable for polypeptide chain elongation in protein synthesis and therefore for cell proliferation. Surprisingly, we could isolate ef2 null cells from Dictyostelium discoideum that exhibited almost normal growth and protein synthesis, which suggests that there is another molecule capable of compensating for EF-2 function. The knock-out of Dictyostelium EF-2 (Dd-EF2H; 101 kDa phosphoprotein) impairs cytokinesis, resulting in formation of multinucleate cells. The initiation of differentiation, including the acquisition of aggregation competence, was delayed in Dd-ef2 null cells compared with that in wild-type. By contrast, Dd-ef2 overexpression enhanced the progression of differentiation, thus indicating a positive involvement of Dd-EF2H in growth/differentiation transition.
Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Japan.
Sohsuke
S
Watanabe
Kohji
K
Sakurai
Aiko
A
Amagai
Yasuo
Y
Maeda
D000818:Animals; D002449:Cell Aggregation / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics*; D002455:Cell Division / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics / Q000648:ultrastructure; D004023:Dictyostelium / Q000166:cytology / Q000378:metabolism*; D015726:Giant Cells / Q000166:cytology / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D020652:Peptide Elongation Factor 2 / Q000172:deficiency* / Q000235:genetics / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D020652:Peptide Elongation Factor 2