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Main Menu - Block
- Overview
- Anatomy and Histology
- Cryo-Electron Microscopy
- Electron Microscopy
- Flow Cytometry
- Gene Targeting and Transgenics
- Immortalized Cell Line Culture
- Integrative Imaging
- Invertebrate Shared Resource
- Janelia Experimental Technology
- Mass Spectrometry
- Media Prep
- Molecular Genomics
- Primary & iPS Cell Culture
- Project Pipeline Support
- Project Technical Resources
- Quantitative Genomics
- Scientific Computing Software
- Scientific Computing Systems
- Viral Tools
- Vivarium
Abstract
Inside the cell, proteins essential for signaling, morphogenesis, and migration navigate the complex, ever-changing environment through vesicular trafficking or microtubule-driven mechanisms. However, the mechanisms by which soluble proteins reach their target destinations remain unknown. Here, we show that soluble proteins are directed toward the cell’s advancing edge by advection, diffusion facilitated by fluid flow. The advective transport mechanism operates in a compartment at the front of the cell isolated from the rest of the cytoplasm by a semi-permeable actin-myosin barrier that restricts protein mixing between the compartment and the rest of the cytoplasm. Contraction at the barrier generates a molecularly non-specific fluid flow that propels treadmilling actin monomer, actin-binding, adhesion, and even inert proteins forward. Changes in the dynamic local curvature of the barrier direct the flow, targeting proteins toward the protruding regions of the leading edge, effectively coordinating the distribution of proteins needed for local changes in cellular dynamics. Outside the compartment, diffusion is the primary mode of soluble protein transport. Our findings suggest that cells possess previously unrecognized organizational strategies for managing soluble protein concentration and distributing them efficiently for activities such as protrusion and adhesion.
