Figure 4.

Immunostaining of various nucleolar antigens on S. pombe cells. (A) Immunodetection with anti-HA antibodies on Sp91 (gar2-null) overexpressing gar2–HA. The nucleolus is normal, and the protein is exclusively nucleolar. (B) Immunodetection with anti-HA antibodies of gar2ΔRBDs overexpressed in Sp91. The truncated protein is both in the large fibrillar nucleolus and in the nucleoplasm. (C and D) Anti-HA (C) and anti-Spgar1 (D) antibodies on Sp91 overexpressing gar2RNP1*. gar2 precisely colocalizes with the dense structures in the nucleolus, which appears larger than these dense zones according to gar1 localization. Bar, 500 nm.