Subcellular localization of mPB and NP-mPB.

Hela cells were transfected with mPB-tGFP or NP-mPB-tGFP expression vectors and immunostained with an anti-cyclin T1 antibody (red) and an anti-fibrillarin antibody (blue). (A) Fluorescence microscopy revealed that mPB was localized in the nucleus, but largely outside the nucleoli, as indicated by the fibrillarin. The cyclin T1 signal was dotted and spared the nucleus. (B) In contrast, NP-mPB was localized in the nucleus, with a strong staining in the nucleoli. There was a dotted pattern of NP-mPB in the nucleus beside the nucleoli. Some of the dots were overlapped with the cyclin T1 signal.