Table 2.

Summary of point mutations of helicase A NTD and their ability for nuclear import and export

MutationAbility for:
Nuclear importaNuclear exportb
Wild type++
P1160A++
Y1179A++
Y1199A++
R1219G++
G1220A++
F1125L++
ΔR1158++
ΔK1162+
ΔR1165+
ΔY1166++
R1165LNDc
  • a The subcellular localization of all mutants was examined with the mutants as GFP fusion proteins. The wild type, ΔR1158, ΔK1162, and ΔR1165 were also studied as Myc-PK fusions.

  • b For all the mutants that retained NLS activity, nuclear export was assayed by accumulation of the GFP fusion proteins in the cytoplasm after treatment with 4 μg of actinomycin D per ml. For ΔK1162 and ΔR1165, nuclear export was assayed in interspecies heterokaryons as both NPc-TNLS fusions and GFP-TNLS fusions.

  • c ND, not determined.