Identification and sequence analysis of a rap gene from the true slime mold Physarum polycephalum.
A member of the ras gene superfamily, belonging to the rap family and designated Pprap1, was isolated from a cDNA library from the true slime mold Physarum polycephalum by plaque hybridization in combination with 5'-RACE. The assembled nucleotide sequence of Pprap1 (1062 bp) has an open reading frame coding for a protein of 188 amino acids of a calculated M(r) of 21035. This protein exhibits: (i) a highly conserved GTP binding domain containing a putative effector domain, with the threonine-for-glutamine substitution characteristic of rap proteins, (ii) a hypervariable domain, and (iii) the CAAX motif. Analysis of the C-terminal amino acid sequence of Pprap1 shows that it presumably undergoes geranylgeranylation but is not palmitoylated; however, it contains a lysine-rich domain which might serve as the second membrane localization signal. Pprap1 exhibits significantly high amino acid homology within the GTP binding domain with its homologues: Ddrap1 from Dictyostelium discoideum (92%) and human Rap1A (83%), and relatively low homology (59%) with the Saccharomyces cerevisiae homologue, RSR1. It has also 59% and 61% homology with the P. polycephalum Ppras1 and Ppras2 proteins, respectively. This gene is the third member of the ras gene superfamily identified in P. polycephalum so far.
Kozlowski
P
P
Institute of Biochemistry, Warsaw University, Poland.
Trzcinska-Danielewicz
J
J
Toczko
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary; D004271:DNA, Fungal; D016054:DNA, Protozoan; D004023:Dictyostelium / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D019204:GTP-Binding Proteins / Q000235:genetics*; D005800:Genes, Fungal; D017125:Genes, Protozoan; D006801:Humans; D008969:Molecular Sequence Data; D016839:Physarum polycephalum / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D020668:rap GTP-Binding Proteins
D017931:DNA Primers; D018076:DNA, Complementary; D004271:DNA, Fungal; D016054:DNA, Protozoan; D005656:Fungal Proteins; D015800:Protozoan Proteins; D019204:GTP-Binding Proteins; D020668:rap GTP-Binding Proteins