Table 1. Nuclear import receptors in the Karyopherin family of proteins.

Human importins (abbreviations/alternative names)	S. cerevisiae importins (alternative names)	NLS
Importin-α/Importin-β (Impα/Impβ/Kapα/Kapβ1)	Kap60/Kap95	Classical-NLS
Karyopherin-β2 (Kapβ2/Transportin-1)	Kap104	PY-NLS
Importin-4 (Imp4/RanBP4)	Kap123	ND#
Importin-5 (Imp5/Kapβ3, Impβ3, RanBP5)	Kap121 (Pse1)	IK-NLS
Importin-7 (Imp7/RanBP7)	Kap119 (Nmd5)	ND
Importin-8 (Imp8/RanBP8)	Kap108 (Sxm1)	ND
Importin-9 (Imp9/RanBP9)	Kap114 (Kapβ)	ND
Importin-11 (Imp11/RanBP11)	Kap120	ND
Transportin-3 (TNPO3/Trn-SR, Imp12)	Kap122 (Pdr6)	RS-NLS
Importin-13* (Imp13/Kap13, RanBP13)		ND
Exportin-4* (Exp4)		ND

^#ND: not determined; * bidirectional transport receptor.