The basic isoform of profilin in pathogenic Entamoeba histolytica

Abstract

In the human parasite Entumoebu histolytica, components of the cytoskeleton are involved in the pathogenicity by their contribution to immune evasion by antibody capping and shedding. In this study, we focus on profilin as a central regulatory component of the cytoskeleton. Profilin was isolated from trophozoites of the pathogenic E. histolytica strain SFL-3, and partial amino acid sequences were used to devise a probe for isolating a profilin cDNA. The deduced complete primary structure was divergent: plant profilins with amino acid sequence identities in the range 33-38% were more closely related than the mammalian profilins with sequence identities 21-28%. The cDNA was expressed as a nonfusion protein in Escherichia coli. Isoelectric focussing of the natural profilin isolated from E. histolytica showed two isoforms with different isoelectric points ; the recombinant profilin migrated with the basic isoform. In a blot overlay experiment, purified 'Z51-labeled recombinant profilin bound not only to plant actin, but also to mammalian actin, demonstrating that cytoskeletal components from distantly related organisms with divergent primary structures can be compatible.

Characterization of Profilin Polymorphism in Pollen with a Focus on Multifunctionality

“…Most of the sequences exhibited hydrophilic character, as indicated by the negative average value (−0.15±0.06) of the calculated Grand index (GRAVY) [31]. Profilin protein sequences could be considered as stable proteins, at the light of the average aliphatic index of 80.03±3.62 [31], and the average stability index (27.95±2.07) [32], where values lower than 40 are considered as a stable protein (Table S1).…”

“…Profilin protein sequences could be considered as stable proteins, at the light of the average aliphatic index of 80.03±3.62 [31], and the average stability index (27.95±2.07) [32], where values lower than 40 are considered as a stable protein (Table S1). …”

How far can we simplify in vitro diagnostics for Fagales tree pollen allergy? A study with three whole pollen extracts and purified natural and recombinant allergens

“…Another factor might be the existence of different isoforms of profilin. Both acidic and basic isoforms of some profilins have been reported [ 28]. Perhaps IgE antibodies can distinguish between different isoforms.…”

Pathogenesis of Intestinal Amebiasis: From Molecules to Disease

“…This suggests an actin feedback-regulatory mechanism, previously described in other cells, where the gene product and the configuration of the microfilaments could directly regulate actin gene expression (85). Evidence for another regulatory mechanism in actin organization is provided by the recent isolation and cDNA cloning of the E. histolytica profilin basic isoform (16). Profilin acts as a buffer in actin organization by either inhibiting or promoting actin filament formation.…”