1. A phagocytosis mutant of Entamoeba histolytica is less virulent due to deficient proteinase expression and release
- Author
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Esther Orozco, D. Scott Herdman, Simona Myers, Ken Hirata, Samuel G. Meléndez-López, Sharon L. Reed, James H. McKerrow, Alok Bhattacharya, Xuchu Que, and Anjan Debnath
- Subjects
Calcium-binding protein 1 ,Transcription, Genetic ,Virulence Factors ,Phagocytosis ,Immunology ,Mutant ,Virulence ,Enzyme-Linked Immunosorbent Assay ,Gene Expression Regulation, Enzymologic ,Microbiology ,Entamoeba histolytica ,parasitic diseases ,Animals ,RNA, Messenger ,Gene ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Calcium-Binding Proteins ,Wild type ,General Medicine ,biology.organism_classification ,Microarray Analysis ,Molecular biology ,Microspheres ,Cysteine Endopeptidases ,Infectious Diseases ,Mutation ,biology.protein ,Parasitology ,RNA, Protozoan ,Cysteine - Abstract
Cysteine proteinases are key virulence factors of Entamoeba histolytica that are released during the process of invasion. We used a chemical mutant of E. histolytica strain HM-1:IMSS, clone L6, which is deficient in virulence, phagocytosis, and cysteine proteinase activity to help define the mechanisms of cysteine proteinase release. All cysteine proteinase genes of wild type HM-1 were present in the L6 mutant genome, but three of the major expressed proteinases, ehcp1, ehcp2, and ehcp5 were both transcribed, translated, and released at lower levels in L6. We hypothesized that a central protein such as the calcium binding protein 1, EhCaBP1, which is required for both phagocytosis and exocytosis might be deficient in this mutant. We found that both mRNA and proteinase levels of EhCaBP1 were decreased in L6. These findings provide an important link between phagocytosis, passive release of multiple cysteine proteinases, and attenuated virulence of this E. histolytica mutant.
- Published
- 2006