scholarly journals Illumination on the structure and characteristics of Entamoeba histolytica genome.

2021 ◽  
Vol 26 (4) ◽  
pp. 19-26
Author(s):  
Musafer Al-Ardi
Keyword(s):  
Cell Division ◽  
Entamoeba Histolytica ◽  
Cysteine Protease ◽  
Extra Chromosome ◽  
Gene Families ◽  
Susceptibility To Infection ◽  
Internal Repeat ◽  
Large Families

Entamoeba histolytica, likes other Organismes, is characterized by diversity and heterogeneity in its genetic content, which is one of the most paramount reasons for survival, and the increase in susceptibility to infection. Non-condensation of chromosomes during the process of cell division and the ambiguity of the chromosomal ploidy makes predicting the exact chromosomal numeral difficult. Genes distributed across 14 chromosomes as well as many extra-chromosome elements. Most Genes compose of one axon only, with Introns in 25% of Genes. This genome is characterized by the presence of Polymorphic internal repeat regions, and several gene families, one of these large families encoding Transmembrane kinas, Cysteine protease (CP), SREHP protein, and others.

scholarly journals Illumination on the Structure and Characteristics of Entamoeba Histolytica Genome

2021 ◽  
Author(s):  
Musafer H. Al-Ardi
Keyword(s):  
Cell Division ◽  
Entamoeba Histolytica ◽  
Cysteine Protease ◽  
Extra Chromosome ◽  
Gene Families ◽  
Chromosomal Number ◽  
Internal Repeat ◽  
Large Families

Entamoeba histolytica, like other Organismes, is characterized by diversity and heterogeneity in its genetic content, which is one of the most important reasons for survival, and the increase in susceptibility to infection.Non-condensation of chromosomes during the process of cell division and the ambiguity of the chromosomal ploidy makes predicting the exact chromosomal number difficult. Genes distributed across 14 chromosomes as well as many extra-chromosome elements. Most Genes composed of one axon only, with Introns in 25% of Genes. This genome is characterized by the presence of Polymorphic internal repeat regions, and several gene families, one of these large families encoding Transmembrane kinas, Cysteine protease (CP), SREHP protein, and others.

scholarly journals Entamoeba histolytica Encodes Unique Formins, a Subset of Which Regulates DNA Content and Cell Division

2008 ◽  
Vol 76 (6) ◽  
pp. 2368-2378 ◽  
Author(s):  
Shubhra Majumder ◽  
Anuradha Lohia
Keyword(s):  
Cell Division ◽  
Sequence Analysis ◽  
Entamoeba Histolytica ◽  
Dna Content ◽  
Actin Assembly ◽  
Dynamic Changes ◽  
Serum Factors ◽  
Multinucleated Cells ◽  
Binucleated Cells ◽  
Cytoskeletal Network

ABSTRACT The formin family of proteins mediates dynamic changes in actin assembly in eukaryotes, and therefore it is important to understand the function of these proteins in Entamoeba histolytica, where actin forms the major cytoskeletal network. In this study we have identified the formin homologs encoded in the E. histolytica genome based on sequence analysis. Using multiple tools, we have analyzed the primary sequences of the eight E. histolytica formins and discovered three subsets: (i) E. histolytica formin-1 to -3 (Ehformin-1 to -3), (ii) Ehformin-4, and (iii) Ehformin-5 to -8. Two of these subsets (Ehformin-1 to -3 and Ehformin-4) showed significant sequence differences from their closest homologs, while Ehformin-5 to -8 were unique among all known formins. Since Ehformin-1 to -3 showed important sequence differences from Diaphanous-related formins (DRFs), we have studied the functions of Ehformin-1 and -2 in E. histolytica transformants. Like other DRFs, Ehformin-1 and -2 associated with F-actin in response to serum factors, in pseudopodia, in pinocytic and phagocytic vesicles, and at cell division sites. Ehformin-1 and -2 also localized with the microtubular assembly in the nucleus, indicating their involvement in genome segregation. While increased expression of Ehformin-1 and -2 did not affect phagocytosis or motility, it clearly showed an increase in the number of binucleated cells, the number of nuclei in multinucleated cells, and the average DNA content of each nucleus, suggesting that these proteins regulate both mitosis and cytokinesis in E. histolytica.

scholarly journals Entamoeba histolytica: a novel cysteine protease and an adhesin form the 112 kDa surface protein

2000 ◽  
Vol 35 (1) ◽  
pp. 248-248
Author(s):  
G. Garcia-Rivera ◽  
M. A. Rodriguez ◽  
R. Ocadiz ◽  
M. C. Martinez-Lopez ◽  
R. Arroyo ◽  
...  
Keyword(s):  
Entamoeba Histolytica ◽  
Cysteine Protease ◽  
Surface Protein

scholarly journals The Intestinal Protozoan Parasite Entamoeba histolytica Contains 20 Cysteine Protease Genes, of Which Only a Small Subset Is Expressed during In Vitro Cultivation

2003 ◽  
Vol 2 (3) ◽  
pp. 501-509 ◽  
Author(s):  
Iris Bruchhaus ◽  
Brendan J. Loftus ◽  
Neil Hall ◽  
Egbert Tannich
Keyword(s):  
Entamoeba Histolytica ◽  
Cysteine Protease ◽  
Cathepsin L ◽  
Protozoan Parasite ◽  
Cysteine Proteases ◽  
Small Subset ◽  
In Vitro Cultivation ◽  
Intestinal Protozoan ◽  
Parasite Life Cycle

ABSTRACT Cysteine proteases are known to be important pathogenicity factors of the protozoan parasite Entamoeba histolytica. So far, a total of eight genes coding for cysteine proteases have been identified in E. histolytica, two of which are absent in the closely related nonpathogenic species E. dispar. However, present knowledge is restricted to enzymes expressed during in vitro cultivation of the parasite, which might represent only a subset of the entire repertoire. Taking advantage of the current E. histolytica genome-sequencing efforts, we analyzed databases containing more than 99% of all ameba gene sequences for the presence of cysteine protease genes. A total of 20 full-length genes was identified (including all eight genes previously reported), which show 10 to 86% sequence identity. The various genes obviously originated from two separate ancestors since they form two distinct clades. Despite cathepsin B-like substrate specificities, all of the ameba polypeptides are structurally related to cathepsin L-like enzymes. None of the previously described enzymes but 7 of the 12 newly identified proteins are unique compared to cathepsins of higher eukaryotes in that they are predicted to have transmembrane or glycosylphosphatidylinositol anchor attachment domains. Southern blot analysis revealed that orthologous sequences for all of the newly identified proteases are present in E. dispar. Interestingly, the majority of the various cysteine protease genes are not expressed in E. histolytica or E. dispar trophozoites during in vitro cultivation. Therefore, it is likely that at least some of these enzymes are required for infection of the human host and/or for completion of the parasite life cycle.

scholarly journals Gene families and evolution of trehalose metabolism in plants

2007 ◽  
Vol 34 (6) ◽  
pp. 550 ◽  
Author(s):  
John E. Lunn
Keyword(s):  
Physcomitrella Patens ◽  
Oryza Sativa L ◽  
Populus Trichocarpa ◽  
Gene Families ◽  
Class I ◽  
Trehalose Metabolism ◽  
Genes Encoding ◽  
Catalytically Active ◽  
Large Families ◽  
Selaginella Moellendorffii

The genomes of Arabidopsis thaliana L., rice (Oryza sativa L.) and poplar (Populus trichocarpa Torr. & A.Gray) contain large families of genes encoding trehalose-phosphate synthase (TPS) and trehalose-phosphatase (TPP). The class I subfamily of TPS genes encodes catalytically active TPS enzymes, and is represented by only one or two genes in most species. A. thaliana is atypical in having four class I TPS genes, three of which (AtTPS2–4) encode unusual short isoforms of TPS that appear to be found only in members of the Brassicaceae family. The class II TPS genes encode TPS-like proteins with a C-terminal TPP-like domain, but there is no experimental evidence that they have any enzymatic activity and their function is unknown. Both classes of TPS gene are represented in the genomes of chlorophyte algae (Ostreococcus species) and non-flowering plants [Physcomitrella patens (Hedw.) Bruch & Schimp.(B.S.G.) and Selaginella moellendorffii (Hieron. in Engl. & Prantl.)]. This survey shows that the gene families encoding the enzymes of trehalose metabolism are very ancient, pre-dating the divergence of the streptophyte and chlorophyte lineages. It also provides a frame of reference for future studies to elucidate the function of trehalose metabolism in plants.

scholarly journals Entamoeba histolytica : a novel cysteine protease and an adhesin form the 112 kDa surface protein

1999 ◽  
Vol 33 (3) ◽  
pp. 556-568 ◽  
Author(s):  
G. Garcia-Rivera ◽  
M. A. Rodriguez ◽  
R. Ocadiz ◽  
M. C. Martinez-Lopez ◽  
R. Arroyo ◽  
...  
Keyword(s):  
Entamoeba Histolytica ◽  
Cysteine Protease ◽  
Surface Protein
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