A selective screen reveals discrete functional domains in Drosophila Nanos.
The Drosophila protein Nanos encodes an evolutionarily conserved protein with two zinc finger motifs. In the embryo, Nanos protein function is required for establishment of the anterior-posterior body pattern and for the migration of primordial germ cells. During oogenesis, Nanos protein is involved in the establishment and maintenance of germ-line stem cells and the differentiation of oocyte precursor cells. To establish proper embryonic patterning, Nanos acts as a translational regulator of hunchback RNA. Nanos' targets for germ cell migration and development are not known. Here, we describe a selective genetic screen aimed at isolating new nanos alleles. The molecular and genetic analysis of 68 new alleles has allowed us to identify amino acids critical for nanos function. This analysis shows that the CCHC motifs, which coordinate two metal ions, are essential for all known functions of Nanos protein. Furthermore, a region C-terminal to the zinc fingers seems to constitute a novel functional domain within the Nanos protein. This "tail region" of Nanos is required for abdomen formation and germ cell migration, but not for oogenesis.
Arrizabalaga
G
G
Biology Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
Lehmann
R
R
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D002465:Cell Movement / Q000235:genetics; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D005260:Female; D019476:Insect Proteins / Q000235:genetics* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000502:physiology; D010641:Phenotype; D016601:RNA-Binding Proteins; D017386:Sequence Homology, Amino Acid; D016335:Zinc Fingers
D029721:Drosophila Proteins; D019476:Insect Proteins; D016601:RNA-Binding Proteins; C070574:nos protein, Drosophila