@article {70335,
	title = {Compartmentalized cytoplasmic tradewinds direct soluble proteins.},
	journal = {Nat Commun},
	volume = {17},
	year = {2026},
	month = {2026 Mar 30},
	abstract = {<p>Proteins essential for signaling, morphogenesis, and migration traverse the complex intracellular landscape via vesicular trafficking, microtubule-based transport, and diffusion. However, the precise mechanisms guiding soluble proteins toward their functional destinations have remained elusive. Here, we demonstrate that soluble proteins are directed toward the cell{\textquoteright}s advancing edge through advection-diffusion enhanced by intracellular fluid flow. We reveal that advective transport occurs within a specialized compartment at the cell{\textquoteright}s leading edge, separated from the rest of the cytoplasm by an actin-myosin condensate barrier. The barrier limits protein mixing between the compartment and the rest of the cytoplasm, maintaining localized protein concentrations. Contraction at the barrier generates a molecularly non-specific fluid flow that drives the forward movement of treadmilling actin monomers, actin-binding proteins, adhesion molecules, and even inert proteins. Dynamic changes in the local curvature of the barrier steer the fluid flow to direct proteins toward protrusive regions of the leading edge. This advective mechanism synchronizes protein distribution with local changes in cell morphology. Outside this compartment, diffusion dominates as the principal mode of soluble protein transport. Our findings uncover previously unrecognized compartmentalization strategies that regulate soluble protein concentrations and coordinate their efficient distribution for homeostasis, protrusion, and adhesion.</p>
},
	keywords = {Actins, Animals, Cell Compartmentation, Cytoplasm, Diffusion, Humans, Myosins, Protein Transport, Solubility},
	issn = {2041-1723},
	doi = {10.1038/s41467-026-70688-6},
	url = {https://doi.org/10.1038/s41467-026-70688-6},
	author = {Galbraith, Catherine G and English, Brian P and Boehm, Ulrike and Galbraith, James A}
}
@article {69441,
	title = {Compartmentalized Cytoplasmic Flows Direct Protein Transport to the Cell{\textquoteright}s Leading Edge},
	journal = {bioRxiv},
	year = {2024},
	month = {2024 May 14},
	abstract = {<p>Inside the cell, proteins essential for signaling, morphogenesis, and migration navigate complex pathways, typically via vesicular trafficking or microtubule-driven mechanisms 1-3. However, the process by which soluble cytoskeletal monomers maneuver through the cytoplasm{\textquoteright}s ever-changing environment to reach their destinations without using these pathways remains unknown. 4-6 Here, we show that actin cytoskeletal treadmilling leads to the formation of a semi-permeable actin-myosin barrier, creating a specialized compartment separated from the rest of the cell body that directs proteins toward the cell edge by advection, diffusion facilitated by fluid flow. Contraction at this barrier generates a molecularly non-specific fluid flow that transports actin, actin-binding proteins, adhesion proteins, and even inert proteins forward. The local curvature of the barrier specifically targets these proteins toward protruding edges of the leading edge, sites of new filament growth, effectively coordinating protein distribution with cellular dynamics. Outside this compartment, diffusion remains the primary mode of protein transport, contrasting sharply with the directed advection within. This discovery reveals a novel protein transport mechanism that redefines the front of the cell as a pseudo-organelle, actively orchestrating protein mobilization for cellular front activities such as protrusion and adhesion. By elucidating a new model of protein dynamics at the cellular front, this work contributes a critical piece to the puzzle of how cells adapt their internal structures for targeted and rapid response to extracellular cues. The findings challenge the current understanding of intracellular transport, suggesting that cells possess highly specialized and previously unrecognized organizational strategies for managing protein distribution efficiently, providing a new framework for understanding the cellular architecture{\textquoteright}s role in rapid response and adaptation to environmental changes.</p>
},
	doi = {10.1101/2024.05.12.593794},
	url = {https://www.biorxiv.org/content/early/2024/05/14/2024.05.12.593794},
	author = {Galbraith, Catherine G and English, Brian P and Boehm, Ulrike and Galbraith, James A}
}
