HOP co-chaperones play a main role in gibberellin signaling
Under specific stress conditions and during different developmental transitions, gibberellins are synthesized by the plant. These phytohormones bind to receptors and are signaled through E3 ligases that contain specific F-box proteins. These E3 ligases, once activated by the hormone, promote the degradation of the transcriptional regulators called DELLA, launching the transcriptional response induced by gibberellins and the physiological processes modulated by the cited hormone.
In this study, we have shown that HOP co-chaperones (HSP70-HSP90 organizing proteins) bind to and facilitate the accumulation and stabilization of SNE, an F-box protein involved in gibberellin signaling. In this way, HOP proteins facilitate the degradation of the DELLA protein RGA, speeding upkey gibberellin-dependent physiological processes, such as germination, flowering or the adaptation of plants to mild temperatures. These studies help us to understand how plants adapt to the global increase of temperature associated to climate change.
Mangano, S., Muñoz, A., Fernández-Calvino, L., Castellano, M.M. 2023. HOP co-chaperones contribute to GA signaling by promoting the accumulation of the F-box protein SNE in Arabidopsis. Plant Communications 100517. DOI: 10.1016/j.xplc.2023.100517