Subcellular distribution in Xenopus laevis oocytes of a microinjected poly(A)-binding protein from Artemia salina...

The poly(A)-binding protein P38 of non-polysomal mRNP from Artemia salina gastrulae was labelled by reductive methylation and microinjected into the cytoplasm of Xenopus laevis oocytes. The labelled protein has a half-life of approximately 20 h and accumulated in the nucleus of the oocyte. The kinetics of accumulation reached a plateau at about 15 h after microinjection. P38 accumulates in the nucleus to a final concentration 3.15 times higher than that reached by free diffusion. This fact suggests that P38, a cytoplasmic poly(A)-binding protein, might also play some role in the nucleus of the cell.