bims-tubesc 2023-03-26 papers

Issue of 2023–03–26
two papers selected by

Trends Endocrinol Metab. 2023 Mar 16. pii: S1043-2760(23)00051-6. [Epub ahead of print]

Regulatory effect of orexin system on various diseases through mTOR signaling pathway.

Ying Song, Beibei Wang, Wenjun Wang, Qiwen Shi.

Orexin (OX)A and OXB are a pair of neuropeptides secreted by orexin-producing neurons in the lateral hypothalamus. The orexin system can regulate many physiological processes through these two receptor pathways, such as feeding behavior, sleep/wake state, energy homeostasis, reward, and the coordination of emotion. Mammalian target of rapamycin (mTOR) can coordinate upstream signals with downstream effectors, thereby regulating fundamental cellular processes and also plays an essential role in the signaling network downstream of the orexin system. In turn, the orexin system can activate mTOR. Here, we review the association of the orexin system with the mTOR signaling pathway mainly by discussing that drugs in various diseases exert their effects on the orexin system, indirectly affecting the mTOR signaling pathway.

Keywords: cerebral ischemia–reperfusion injury; mammalian target of rapamycin; orexin; orexinergic receptor

DOI: https://doi.org/10.1016/j.tem.2023.02.008

Curr Biol. 2023 Mar 20. pii: S0960-9822(23)00291-9. [Epub ahead of print]

ARSK1 activates TORC1 signaling to adjust growth to phosphate availability in Arabidopsis.

Huikyong Cho, Michael Banf, Zaigham Shahzad, Jelle Van Leene, Flavia Bossi, Sandrine Ruffel, Nadia Bouain, Pengfei Cao, Gabiel Krouk, Geert De Jaeger, Benoit Lacombe, Federica Brandizzi, Seung Y Rhee, Hatem Rouached.

Nutrient sensing and signaling are essential for adjusting growth and development to available resources. Deprivation of the essential mineral phosphorus (P) inhibits root growth.1 The molecular processes that sense P limitation to trigger early root growth inhibition are not known yet. Target of rapamycin (TOR) kinase is a central regulatory hub in eukaryotes to adapt growth to internal and external nutritional cues.2,3 How nutritional signals are transduced to TOR to control plant growth remains unclear. Here, we identify Arabidopsis-root-specific kinase 1 (ARSK1), which attenuates initial root growth inhibition in response to P limitation. We demonstrate that ARSK1 phosphorylates and stabilizes the regulatory-associated protein of TOR 1B (RAPTOR1B), a component of the TOR complex 1, to adjust root growth to P availability. These findings uncover signaling components acting upstream of TOR to balance growth to P availability.

Keywords: ARSK1; Arabidopsis; RAPTOR1B; TOR; TORC1 signaling; early signaling; phosphorus deficiency; phosphorylation; root growth

DOI: https://doi.org/10.1016/j.cub.2023.03.005