Sobczak Magdalena, Kocik Elzbieta, Redowicz Maria Jolanta
Nencki Institute of Experimental Biology, Department of Muscle Biochemistry, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland.
Biochem Cell Biol. 2007 Feb;85(1):22-31. doi: 10.1139/o06-177.
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.
在大变形虫中发现了一种新型的120 kDa肌动蛋白结合蛋白（ApABP-F1）。它分布于整个细胞质中，主要位于质膜下和核周-核区域，富含肌动蛋白。ApABP的全长cDNA由2672个核苷酸组成，开放阅读框为878个氨基酸，产生一种约95 kDa的蛋白质，理论pI值为5.11。它具有一种新型的结构域组织模式：N端（第1-104位氨基酸）包含1个钙调蛋白同源（CH）结构域，接着只有1个与细丝蛋白重复序列（FR，第209-324位氨基酸）同源的区域，以及一个中央区域（第344-577位氨基酸），该区域呈现出非常高的形成卷曲螺旋的可能性，可能参与了观察到的蛋白质二聚化。对25种不同蛋白质的CH结构域构建的系统发育树表明，ApABP的CH结构域与假定的小鼠KIAA0903样蛋白的CH结构域关系最为密切，而与盘基网柄菌和溶组织内阿米巴的细丝蛋白或凝胶化因子（ABP-120）均无明显关系。
