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ABSTRACT: α-Actinins form antiparallel homodimers that are able to cross-link actin filaments. The protein contains three domains: an N-terminal actin-binding domain followed by a central rod domain and a calmodulin-like EF-hand domain at the C-terminus. Here, crystallization of the rod domain of Entamoeba histolytica α-actinin-2 is reported; it crystallized in space group P2(1)2(1)2(1), with unit-cell parameters a = 47.8, b = 79.1, c = 141.8 Å. A Matthews coefficient V(M) of 2.6 Å(3) Da(-1) suggests that there are two molecules and 52.5% solvent content in the asymmetric unit. A complete native data set extending to a d-spacing of 2.8 Å was collected on beamline I911-2 at MAX-lab, Sweden.
Acta Crystallographica Section F Structural Biology and Crystallization Communications 10/2011; 67(Pt 10):1214-7. · 0.51 Impact Factor
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ABSTRACT: Entamoeba histolytica, a major agent of human amoebiasis, expresses two distinct forms of α-actinin, a ubiquitous actin-binding protein that is present in most eukaryotic organisms. In contrast to all metazoan α-actinins, in both isoforms the intervening rod domain that connects the N-terminal actin-binding domain with the C-terminal EF-hands is much shorter. It is suggested that these α-actinins may be involved in amoeboid motility and phagocytosis, so we cloned and characterised each domain of one of these α-actinins to better understand their functional role. The results clearly showed that the domains have properties very similar to those of conventional α-actinins.
Cellular & Molecular Biology Letters 12/2010; 15(4):665-78. · 1.50 Impact Factor
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ABSTRACT: We have cloned and characterized a second alpha-actinin isoform in Entamoeba histolytica. This protein, alpha-actinin2, has a N-terminal actin-binding domain, a C-terminal calcium-binding domain and an intervening rod domain containing two spectrin repeats. The protein binds and cross-links actin filaments in a calcium-dependent manner. Therefore alpha-actinin2 is a genuine alpha-actinin except for the shorter rod domain compared to the rod domain of isoforms of higher organisms. A alpha-actinin-like protein has previous been implicated in the adherence to the host cell and infection. It is therefore possible that alpha-actinin2 is involved in mechanism of infection, and in particular in reorganisation of the parasite's cytoskeleton that follows on adherence. E. histolytica alpha-actinin2 represents one of the first members of the spectrin superfamily where well defined spectrin repeats are found. The isolation and characterization of this second alpha-actinin isoform is valuable not only into the study of E. histolytica infection mechanisms, but also for understanding the evolution processes of the spectrin superfamily.
Molecular and Biochemical Parasitology 08/2007; 154(1):82-9. · 2.55 Impact Factor
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ABSTRACT: We have cloned and characterized a second α-actinin isoform in Entamoeba histolytica. This protein, α-actinin2, has a N-terminal actin-binding domain, a C-terminal calcium-binding domain and an intervening rod domain containing two spectrin repeats. The protein binds and cross-links actin filaments in a calcium-dependent manner. Therefore α-actinin2 is a genuine α-actinin except for the shorter rod domain compared to the rod domain of isoforms of higher organisms.A α-actinin-like protein has previous been implicated in the adherence to the host cell and infection. It is therefore possible that α-actinin2 is involved in mechanism of infection, and in particular in reorganisation of the parasite's cytoskeleton that follows on adherence.E. histolytica α-actinin2 represents one of the first members of the spectrin superfamily where well defined spectrin repeats are found. The isolation and characterization of this second α-actinin isoform is valuable not only into the study of E. histolytica infection mechanisms, but also for understanding the evolution processes of the spectrin superfamily.
Molecular and Biochemical Parasitology.
