Ingestion of Food Particles Regulates the Mechanosensing Misshapen-Yorkie Pathway in Drosophila Intestinal Growth

Publication date: Available online 10 May 2018
Source:Developmental Cell
Author(s): Qi Li, Niraj K. Nirala, Yingchao Nie, Hsi-Ju Chen, Gary Ostroff, Junhao Mao, Qi Wang, Lan Xu, Y. Tony Ip
The intestinal epithelium has a high cell turnover rate and is an excellent system to study stem cell-mediated adaptive growth. In the Drosophila midgut, the Ste20 kinase Misshapen, which is distally related to Hippo, has a niche function to restrict intestinal stem cell activity. We show here that, under low growth conditions, Misshapen is localized near the cytoplasmic membrane, is phosphorylated at the threonine 194 by the upstream kinase Tao, and is more active toward Warts, which in turn inhibits Yorkie. Ingestion of yeast particles causes a midgut distention and a reduction of Misshapen membrane association and activity. Moreover, Misshapen phosphorylation is regulated by the stiffness of cell culture substrate, changing of actin cytoskeleton, and ingestion of inert particles. These results together suggest that dynamic membrane association and Tao phosphorylation of Misshapen are steps that link the mechanosensing of intestinal stretching after food particle ingestion to control adaptive growth.

Teaser

Yeast is a natural food source for fruit flies, and accumulation of yeast particles in their midgut causes expansion of the gut tube. Li et al. show that such expansion triggers a mechanosensing mechanism leading to the relief of inhibition of Yorkie-mediated tissue growth by the upstream kinase Misshapen.


https://ift.tt/2rAmN9D