Uncovering the principles coordinating systems-level organelle biogenesis with cellular growth.

Abstract

A complete framework of eukaryotic cellular growth control must include the growth of its defining hallmarks: organelles. Organelle coordination with cellular growth is opaque without measuring multiple organelles in the same cell with adequate statistics to test theoretical frameworks. Here, we map out the correlation structure of systems-level organelle biogenesis with cellular growth using "rainbow yeast," simultaneously visualizing 6 major metabolically active organelles. Hyperspectral imaging of thousands of rainbow yeast cells revealed that systems-level organelle biogenesis is organized into collective organelle modes activated by changes in nutrient availability. Chemical biological dissection suggests that sensed growth rate and cell size specifically activate these organelle modes. Mathematical modeling and synthetic control of cytoplasmic availability suggest that the organelle mode structure allows growth homeostasis in constant environments and responsiveness to environmental change. This regulatory architecture may underlie how compartmentalization allows cell size and growth rate flexibility to satisfy otherwise incompatible environmental and developmental constraints.