Figure 4. In vivo localization studies on Hepatitis B surface protein (HBsAg) expressed in P. tricornutum.

HBsAg fused to GFP accumulates in punctual patterns, which partially co-localize with an ER-membrane protein (Der1-2) that was expressed as CFP fusion. The ER in P. tricornutum normally spans the whole cell, but is rather atypically aggregated in these clones. Punctual Fluorescence of HBsAg might be due to the formation of virus like particles (VLPs). Scale bar represents 10 µm. PAF – plastid autofluorescence.