Relocalization of the dorsal protein from the cytoplasm to the nucleus correlates with its function.
dorsal is one of the maternally active dorsal-ventral polarity genes of Drosophila and is homologous to the vertebrate proto-oncogene c-rel. In wild-type embryos, the dorsal protein is found in the cytoplasm during cleavage. After the nuclei migrate to the periphery of the embryo, a ventral-to-dorsal gradient of nuclear dorsal protein is established. The formation of the nuclear gradient is disrupted in mutant embryos from other maternally active dorsal-ventral polarity genes: in dorsalized embryos only cytoplasmic protein is observed, while in ventralized embryos the nuclear gradient is shifted dorsally. My findings suggest that nuclear localization is critical for dorsal to function as a morphogen and that the distribution of the dorsal protein determines cell fate along the dorsal-ventral axis.
Steward
R
R
Biology Department, Princeton University, New Jersey 08544.
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins; D011499:Protein Processing, Post-Translational; D014157:Transcription Factors
D029721:Drosophila Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D014157:Transcription Factors; C062236:dl protein, Drosophila