Sg. Nadler et al., DIFFERENTIAL EXPRESSION AND SEQUENCE-SPECIFIC INTERACTION OF KARYOPHERIN-ALPHA WITH NUCLEAR-LOCALIZATION SEQUENCES, The Journal of biological chemistry, 272(7), 1997, pp. 4310-4315
The process of nuclear protein transport requires the interaction of s
everal different proteins, either directly or indirectly with nuclear
localization or targeting sequences (NLS). Recently, a number of karyo
pherins alpha, or NLS-binding proteins, have been identified. We have
found that the karyopherins hSRP1 and hSRP1 alpha are differentially e
xpressed in various leukocyte cell lines and could be induced in norma
l human peripheral blood lymphocytes, We show that the two karyopherin
s bind with varied specificities in a sequence specific manner to diff
erent NLSs and that the sequence specificity is modulated by other cyt
osolic proteins. There was a correlation between binding of karyopheri
ns cu to different NLSs and their ability to be imported into the nucl
eus. Taken together, these data provide evidence for multiple levels o
f control of the nuclear import process.