Refining the nuclear localization signal within the Egr transcriptional coregulator NAB2.

NAB1 and 2 are coregulators for early growth response (Egr) transcription factors. The NAB1 nuclear localization signal (NLS) was previously described as a bipartite NLS of sequence R(X )K(X )KRXK. The sequence is conserved in NAB2 as K(X )R(X )KKXK; however, whether it functions as the NAB2 NLS has not been tested.