Growing and developing Dictyostelium cells express different ras genes.
The expression of ras-related protein in the cellular slime mold Dictyostelium discoideum is developmentally regulated. It was previously reported that Dictyostelium possesses a single ras gene (Ddras) that is maximally expressed during the pseudoplasmodial stage of development. We have isolated a series of cDNA clones derived from a second ras gene, DdrasG. It encodes a protein that is very similar to the protein encoded by Ddras, but in contrast to Ddras, DdrasG is only expressed during growth and early development. Although other eukaryotic organisms possess more than one ras gene, Dictyostelium is thus far unique in expressing different ras genes at different stages of development. In Dictyostelium the two ras proteins may fulfill different functions, with the DdrasG protein playing a role during cell growth and the Ddras protein playing a role in signal transduction during multicellular development.
Robbins
S M
SM
Department of Microbiology, University of British Columbia, Vancouver, Canada.
Williams
J G
JG
Jermyn
K A
KA
Spiegelman
G B
GB
Weeks
G
G
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004023:Dictyostelium / Q000235:genetics* / Q000254:growth & development; D005656:Fungal Proteins / Q000235:genetics*; D005796:Genes; D005800:Genes, Fungal; D011905:Genes, ras; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D014158:Transcription, Genetic; D018631:ras Proteins
D005656:Fungal Proteins; D012333:RNA, Messenger; C489016:ras protein, Dictyostelium; D018631:ras Proteins