The WPP domain is a protein domain thought to be exclusively found in plants, first identified in 2000.[1] The domain is about 90 amino acid residues long.
The domain is known to direct RanGAP to the nuclear envelope.[2] Non-RanGAP nuclear envelope proteins are also known to encode WPP domains, such as MFP1 attachment factor 1 (MAF1),[1] WPP1[3] and WPP2.[3]
The WPP stands for a tryptophan-proline-proline motif that is highly conserved in the domain.[1] Either deletion of the WPP domain or mutation of both the namesake tryptophan and first proline residues into alanine in the Arabidopsis thaliana protein RanGAP1 leads to mis-targeting in the majority of cells.[2]