Studies on the transcription, translation, and structure of alpha-actinin in Dictyostelium discoideum.
A clone coding for the F-actin cross-linking protein alpha-actinin was obtained by screening a genomic library of Dictyostelium discoideum DNA in lambda gt11 with monoclonal antibodies specific for Dictyostelium alpha-actinin. The 1.2-kilobase (kb) genomic clone was confirmed as containing part of the alpha-actinin gene by comparing its nucleotide sequence with the amino acid sequence of tryptic peptides from purified alpha-actinin. The clone recognized a 3.0-kb message in a Northern blot. Hybridization to RNA isolated from different developmental stages of several D. discoideum strains indicated that the mRNA content increased during early development. A similar result was obtained when the alpha-actinin content of the cells was followed by Western blot analysis. Hybridization of the clone to DNA from different wild-type strains of D. discoideum indicated a polymorphism on the DNA level that coincided with a polymorphism on the protein level. The data suggest continuous transcription of the alpha-actinin gene throughout the development of D. discoideum, up- and down-regulation of the levels of alpha-actinin mRNA and protein with maximum levels at the onset of aggregation, and a high diversity of alpha-actinin at the DNA and protein level among different D. discoideum strains. The structural data make it conceivable that the highly conserved nature of alpha-actinin resides only at the functional sites, whereas the helical portions of the alpha-actinin molecule allow a higher level of diversity throughout evolution.
D000185:Actinin / Q000032:analysis / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D004271:DNA, Fungal / Q000032:analysis; D004023:Dictyostelium / Q000032:analysis* / Q000235:genetics; D011110:Polymorphism, Genetic; D014176:Protein Biosynthesis; D011487:Protein Conformation; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics; D014158:Transcription, Genetic
D004271:DNA, Fungal; D012331:RNA, Fungal; D012333:RNA, Messenger; D011994:Recombinant Proteins; D000185:Actinin