Biology subjects

Tillman, M.

Publications and source records attributed to Tillman, M..

2 recordsLinked to original sources

bioRxiv2021

Lysosome Lipid Signaling from the Periphery to Neurons Regulates Longevity

Lysosomes are key cellular organelles that metabolize extra- and intracellular substrates. Alterations in lysosomal metabolism are implicated in aging-associated metabolic and neurodegenerative diseases. However, how lysosomal metabolism actively coordinates the metabolic and nervous systems to regulate aging remains unclear. Here, we report a fat-to-neuron lipid signaling pathway induced by lysosomal metabolism and its longevity promoting role in Caenorhabditis elegans. We discovered that lysosomal lipolysis in peripheral fat storage tissue up-regulates the neuropeptide signaling pathway in the nervous system to promote longevity. This cell-non-autonomous regulation requires the secretion from the fat storage tissue of a lipid chaperone protein LBP-3 and polyunsaturated fatty acids (PUFAs). LBP-3 binds to specific PUFAs, and acts through a nuclear hormone receptor NHR-49 and neuropeptide NLP-11 in neurons to extend lifespan. Together, these results reveal lysosomes as a signaling hub to coordinate metabolism and aging, and a lysosomal signaling mechanism that mediates intertissue communication to promote longevity.

cell biology↗

bioRxiv2021

Biphasic Control of Cell Expansion by Auxin Coordinates Etiolated Seedling Development

Seedling emergence is critical for food security. It requires rapid hypocotyl elongation and apical hook formation, both of which are mediated by regulated cell expansion. How these events are coordinated in etiolated seedlings is unclear. Here, we show that biphasic control of cell expansion by the phytohormone auxin underlies this process. Shortly after germination, high auxin levels restrain elongation. This provides a temporal window for apical hook formation, involving a gravity-induced auxin maximum on the eventual concave side of the hook, triggering PP2C.D1controlled asymmetrical H+-ATPase activity, resulting in differential cell elongation. Subsequently, auxin concentrations decline acropetally and switch from restraining to promoting elongation, driving hypocotyl elongation. Our findings elucidate how differential auxin concentrations throughout the hypocotyl coordinate etiolated development, leading to successful soil emergence. One-Sentence SummaryAuxin concentration-dependent cell expansion coordinates hypocotyl elongation and apical hook development for soil emergence.

plant biology↗