A Novel Homozygous Mutation of Thyroid Peroxidase Gene Abolishes a Disulfide Bond Leading to Congenital Hypothyroidism

Figure 5

Immunocytochemical analysis of HEK293 cells. Location of wild-type and mutant TPO proteins. To determine the localization of TPO protein, immunofluorescence experiments were performed. Fluorescence was detected in the cells expressing wild-type TPO (WT), p.Cys655Phe (Mut) in both permeabilized and unpermeabilized conditions. (a) Compared under the condition of nonpermeabilized, TPO was localized in the endoplasmic reticulum in both WT and Mut. Cells transfected with the empty vector (control) did not show TPO fluorescence. The TPO is green, the endoplasmic reticulum is red, and the nucleus is purple. (b) WT and Mut were compared under the permeabilized condition (left) and the nonpermeabilized condition (right). There was no significant difference in the localization of TPO between the two types of cells. The presence of TPO was confirmed on the cell membrane surface under nonpermeabilized conditions and on the endoplasmic reticulum under permeabilized conditions. The white bar shows 10 μm.

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