Which of the following results provided evidence of a discrete nuclear localization signal somewhere on the nucleoplasmin protein?
a. the srp bound only to the tail of the nucleoplasmin protein, not the core segment.
b. after cleavage of the nucleoplasmin protein, only the tail segments appeared in the nucleus.
c. the nucleoplasmin protein was small and easily slipped through the nuclear pore complex.
d. the core fragments were transported through dynamic gates across the nuclear envelope