title: Identification of an actin-binding protein from Dictyostelium as elongation factor 1a.
abstract: Indirect evidence has implicated an interaction between the cytoskeleton and the protein synthetic machinery. Two recent reports have linked the elongation factor 1a (EF-1a) which is involved in protein synthesis, with the microtubular cytoskeleton. In situ hybridization has, however, revealed that the messages for certain cytoskeletal proteins are preferentially associated with actin filaments. ABP-50 is an abundant actin filament bundling protein of native relative molecular mass 50,000 (50K) isolated from Dictyostelium discoideum. Immunofluorescence studies show that ABP-50 is present in filopodia and other cortical regions that contain actin filament bundles. In addition, ABP-50 binds to monomeric actin in the cytosol of unstimulated cells and the association of ABP-50 with the actin cytoskeleton is regulated during chemotaxis. Through complementary DNA sequencing and subsequent functional analysis, we have identified ABP-50 as D. discoideum EF-1a. The ability of EF-1a to bind reversibly to the actin cytoskeleton upon stimulation could provide a mechanism for spatially and temporally regulated protein synthesis in eukaryotic cells.
authors.affiliation: Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461.
authors.forename: F
authors.initials: F
authors.lastname: Yang
authors.forename: M
authors.initials: M
authors.lastname: Demma
authors.forename: V
authors.initials: V
authors.lastname: Warren
authors.forename: S
authors.initials: S
authors.lastname: Dharmawardhane
authors.forename: J
authors.initials: J
authors.lastname: Condeelis
mesh_terms: D000595:Amino Acid Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004023:Dictyostelium / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics; D005800:Genes, Fungal; D008840:Microfilament Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000235:genetics / Q000502:physiology*; D014176:Protein Biosynthesis; D012331:RNA, Fungal / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D008840:Microfilament Proteins; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D012331:RNA, Fungal; D004247:DNA