Korean J Parasitol.  2007 Sep;45(3):165-174. 10.3347/kjp.2007.45.3.165.

Nucleolar translocalization of GRA10 of Toxoplasma gondii transfectionally expressed in HeLa cells

• Ahn HJ
• Kim S
• Nam HW

• KMID: 1104526
• DOI: http://doi.org/10.3347/kjp.2007.45.3.165

Abstract

Toxoplasma gondii GRA10 expressed as a GFP-GRA10 fusion protein in HeLa cells moved to the nucleoli within the nucleus rapidly and entirely. GRA10 was concentrated specifically in the dense fibrillar component of the nucleolus morphologically by the overlap of GFP-GRA10 transfection image with IFA images by monoclonal antibodies against GRA10 (Tg378), B23 (nucleophosmin) and C23 (nucleolin). The nucleolar translocalization of GRA10 was caused by a putative nucleolar localizing sequence (NoLS) of GRA10. Interaction of GRA10 with TATA-binding protein associated factor 1B (TAF1B) in the yeast two-hybrid technique was confirmed by GST pull-down assay and immunoprecipitation assay. GRA10 and TAF1B were also co-localized in the nucleolus after co-transfection. The nucleolar condensation of GRA10 was affected by actinomycin D. Expressed GFP-GRA10 was evenly distributed over the nucleoplasm and the nucleolar locations remained as hollows in the nucleoplasm under a low dose of actinomycin D. Nucleolar localizing and interacting of GRA10 with TAF1B suggested the participation of GRA10 in rRNA synthesis of host cells to favor the parasitism of T. gondii.

Keyword

Toxoplasma gondii; GRA10; transfection; nucleolar localization; NoLS; TAF1B; rRNA synthesis

MeSH Terms

Alpha-Amanitin/pharmacology
Animals
Antibodies, Monoclonal/analysis/metabolism
Antibodies, Protozoan/analysis/metabolism
Dactinomycin/pharmacology
Fluorescent Antibody Technique, Direct
Gene Expression/*physiology
Green Fluorescent Proteins/genetics
Hela Cells
Humans
Mice
Mice, Inbred BALB C
Nucleic Acid Synthesis Inhibitors/pharmacology
Nucleolus Organizer Region/drug effects/*metabolism
Pol1 Transcription Initiation Complex Proteins/metabolism
Protein Sorting Signals/physiology
Protozoan Proteins/*biosynthesis/genetics/metabolism
Recombinant Fusion Proteins/genetics/metabolism
Toxoplasma/*physiology
Transfection