title: A novel Amoeba proteus 120 kDa actin-binding protein with only 1 filamin repeat and a coiled-coil region.
abstract: A novel 120 kDa actin-binding protein (ApABP-F1) was found in Amoeba proteus. It was distributed throughout the cytoplasm, mainly in the subplasma membrane and perinuclear-nuclear areas, enriched in actin. The full-length cDNA of ApABP consisted of 2672 nucleotides with an open reading frame of 878 amino acids, giving a ~95 kDa protein with a theoretical pI value of 5.11. It had a novel domain organization pattern: the N terminus (residues 1-104) contained 1 calponin-homology (CH) domain, followed by only 1 region that was homologous to the filamin repeat (FR, residues 209-324), and a central region (residues 344-577) exhibiting a very high probability of coiled-coil formation, probably engaged in the observed protein dimerization. A phylogenetic tree constructed for CH domains from 25 various proteins revealed that the CH domain of ApABP was most related to that of the hypothetical mouse KIAA0903-like protein, whereas not much relationship to either filamins or the gelation factor (ABP-120) of Dictyostelium discoideum and Entamoeba histolytica was found.
authors.affiliation: Nencki Institute of Experimental Biology, Department of Muscle Biochemistry, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sobczak
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Kocik
authors.forename: Maria Jolanta
authors.initials: MJ
authors.lastname: Redowicz
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000656:Amoeba / Q000378:metabolism*; D000818:Animals; D003285:Contractile Proteins / Q000235:genetics*; D018076:DNA, Complementary; D019281:Dimerization; D064448:Filamins; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D003285:Contractile Proteins; D018076:DNA, Complementary; D064448:Filamins; D008840:Microfilament Proteins; D015800:Protozoan Proteins