Ideas

Eukaryotic cells exert remarkable control over their architecture. This is fundamentally important for cell growth, migration, and division, and is critical for the formation and maintenance of functional tissues. Networks of conserved signaling proteins accomplish this control, which requires coordination of processes as diverse as cytoskeleton assembly, membrane trafficking, and gene expression.

Cell morphology is also intertwined with differentiation of diverse cell types. Cell fate asymmetry can arise through unequal partitioning of intracellular determinants that impart a specific gene expression program. These determinants are often direct regulators of transcription, but they can also be molecules or structures that change the cell's sensitivity to external signals. Determinant asymmetry is generated by mechanisms that work with the cell's underlying architecture to move them to one daughter cell or specify the plane of cell division to ensure their unequal partitioning.

How, then, is cell architecture controlled and linked to the mechanisms that specify cell fate? Answering this question requires tracing the exact flow of regulatory information through networks of signaling proteins that coordinate diverse processes in space and time. We are approaching this problem in the budding yeast Saccharomyces cerevisiae, a simple eukaryote in which signaling pathways fundamentally important in cell morphogenesis are conserved.