PT  - JOURNAL ARTICLE
AU  - Adelita D. Mendoza
AU  - Nicholas Dietrich
AU  - Chieh-Hsiang Tan
AU  - Daniel Herrera
AU  - Jennysue Kasiah
AU  - Zachary Payne
AU  - Daniel L. Schneider
AU  - Kerry Kornfeld
TI  - Lysosome-related organelles contain an expansion compartment that mediates delivery of zinc transporters to promote homeostasis
AID  - 10.1101/2021.09.18.460850
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.09.18.460850
4099  - http://biorxiv.org/content/early/2021/09/19/2021.09.18.460850.short
4100  - http://biorxiv.org/content/early/2021/09/19/2021.09.18.460850.full
AB  - Lysosome-related organelles play evolutionarily conserved roles in zinc storage, but mechanisms that control zinc flow in and out are not well understood. In C. elegans intestinal cells, the CDF-2 transporter stores zinc in these organelles during excess. Here we identify ZIPT-2.3 as the transporter that releases zinc during deficiency. The expression levels of CDF-2 and ZIPT-2.3 are reciprocally regulated in zinc excess and deficiency, establishing a fundamental mechanism of homeostasis. Super-resolution microscopy demonstrated these organelles are composed of a spherical acidified compartment and a hemispherical expansion compartment. The expansion compartment inflates during zinc excess and deficiency by vesicle fusion delivering zinc transporters. These results identify an unexpected structural feature of lysosome-related organelles that facilitates rapid transitions in the composition of zinc transporters to mediate homeostasis.Competing Interest StatementThe authors have declared no competing interest.