The abstract is read at the publisher; the summary is JClub's.
Loss of the coiled-coil protein GTRD reverses protonemal gravitropism in Physcomitrium patens, revealing that a kinesin-14–linked transport system is required for correct upward growth direction.
- Why it matters: Moss protonemata show gravitropic reorientation, but the asymmetric molecular process that produces directional growth cues is unclear.
- What they did: A forward genetic screen identified GTRD; GTRD was shown to complex with kinesin-14 GTRC, with GTRC driving minus-end-directed movement of GTRD along microtubules. The complex transports MSD1-WDR8 to position katanin, and gravistimulation triggers katanin-dependent microtubule severing that forms an upper-flank microtubule focus.
- The result: Katanin-mediated microtubule remodeling spatially constrains the apical actin cluster, guiding upward protonemal growth and linking GTRC–GTRD–katanin microtubule organization to cytoskeletal polarity during gravitropism.
The findingWhy it mattersWhat they didThe result
AI summary of the abstract · may contain errors · not medical advice · read the paper.