InterPro domain: IPR044806

This entry includes WAVE-DAMPENED2 (WVD2) and WDL1/2/3. WVD2, and its closest paralogue WDL1, modulate both rotational polarity and anisotropic cell expansion during organ growth and also promote clockwise root and etiolated hypocotyls coiling, clockwise leaf curling, but left-handed petiole twisting [ 1 , 2 ]. WDL3 stabilises microtubules, playing an important role in the regulation of hypocotyl cell elongation. WDL3 levels are regulated by an ubiquitin-26S proteasome–dependent pathway in response to light and functions as a negative regulator of hypocotyl cell elongation in the light [ 3 ].In animals, Targeting Protein for Xklp2 (TPX2) is critical for mitotic spindle assembly. It has a highly conserved TPX2 central domain, an Aurora-A binding domain and a TPX2_C domain that contains a conserved pentapeptide KLEEK motif. However, in plants besides the TPX2 homologue (with three domains), several proteins were found with only the TPX2_C domain. This group of TPX2_C domain only proteins in plants has been named as WDL (or WVD2-like) proteins, as the first identified member is known as WVD2. These WDL proteins bind to microtubules; however, they have lost the function of targeting Xklp2 and were found to play roles in plant development and responses to environment cues [ 4 , 4 ].

1. WVD2 and WDL1 modulate helical organ growth and anisotropic cell expansion in Arabidopsis. Plant Physiol. 131, 493-506
2. WVD2 is a novel microtubule-associated protein in Arabidopsis thaliana. Plant J 49, 961-71
3. Light-regulated hypocotyl elongation involves proteasome-dependent degradation of the microtubule regulatory protein WDL3 in Arabidopsis. Plant Cell 25, 1740-55
4. Ethylene Regulates the Arabidopsis Microtubule-Associated Protein WAVE-DAMPENED2-LIKE5 in Etiolated Hypocotyl Elongation. Plant Physiol 169, 325-37