[Paul Verslues] A new class of plant GTPase with roles in intracellular trafficking.
POST:
The NPH3-domain protein NRL5 participates in intracellular trafficking and is required for correct regulation of proline metabolism and drought stress resistance.
A forward genetic screen conducted in the Verslues laboratory found that mutation of the Non-Phototrophic Hypocotyl3 (NPH3)-domain protein NRL5 causes plants to become hypersensitive to drought stress because of mis-regulated proline metabolism. Further experiments found that NRL5 and other NPH3-domain proteins have GTPase activity despite having no similarity to known GTPases. NRL5 also interacted with proteins involved in vesicle trafficking. These results are the first to establish a cellular function for the plant specific NPH3 domain (Upadhyay-Tiwari et al., 2024). In addition to establishing a new aspect of drought-related signaling, these results will also allow a critical re-evaluation of how NPH3-domain proteins function in key signaling pathways such as light and auxin response and will help define the cellular function of many other uncharacterized NPH3-domain proteins (Verslues and Upadhyay-Tiwari, 2024).