Giardia intestinalis Elongation Factor 1-alpha is released during host cell interaction

• Giardia intestinalis is an intestinal diarrhea-causing parasite but the disease mechanism is not fully understood. Here we used SDS-PAGE gels and MALDI-TOF analysis to identify proteins released by Giardia trophozoites during axenic growth with and without host cells. We detected serum proteins that bind strongly to the parasite surface but also two Giardia proteins: elongation factor-1 alpha (EF-1α) and a 58kDa protein identified as arginine deiminase (ADI). Two genes encoding EF-1α were detected in the Giardia WB genome 35kbp apart. The coding sequences are identical but the promoter and 3’ regions differ. Promoter luciferase-fusions showed that both genes are transcribed in trophozoites. The EF-1α protein localizes to the ER region but it relocalizes to the plasma membrane and is secreted during host cell interaction. Recombinant EF-1α is recognized by serum from giardiasis patients. Our results suggest that EF-1α is important during Giardia infections and that ADI can be the earlier identified 58kDa enterotoxin.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Infektionsmedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Infectious Medicine (hsv//eng)

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Keyword

Infectious diseases

Infektionssjukdomar

Cell and molecular biology

Cell- och molekylärbiologi

mikrobiologi

Microbiology

Publication and Content Type

ref (subject category)

ovr (subject category)