Molecular Assembly Lines in Active Droplets

 

Cells assemble structures that have lots of molecules. How can such complicated structures be reliably assembled? We propose that cells could be organizing an assembly line process for the construction. We show how this could be organized inside droplets. In this video we explain our recent work published in PRL. Check out the paper for more info: https://journals.aps.org/prl/abstract...

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

 

A quick intro to the Phase Diagram

Phase Diagrams are graphic representations that help understand many physical systems such as magnets and pure substances like water. These diagrams also help us understand how dense droplets of biomolecules, called Biomolecular Condensates, form inside cells. Phase Diagrams predict under which conditions these condensates can form and also what will be their molecular concentration. Watch this quick intro to learn more! References: -Video C. Elegans: Fritsch, Diaz-Delgadillo, Adame-Arana et al., PNAS (2021) https://www.pnas.org/doi/10.1073/pnas... -Multicomponent Phase Diagram: Bauerman, Laha, McCall, and Weber JACS (2022) https://pubs.acs.org/doi/pdf/10.1021/...

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

 

A quick intro to Entropy

Have you ever seen a tepid cup of coffee getting hot? Or a pile of sand grains organizing themselves into a sand castle? It would be strange, right? But why? The reason is behind one of the most fundamental and general laws of physics: The Second Law of Thermodynamics.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

 

A quick intro to the Second Law of Thermodynamics

Have you ever seen a tepid cup of coffee getting hot? Or a pile of sand grains organizing themselves into a sand castle? It would be strange, right? But why? The reason is behind one of the most fundamental and general laws of physics: The Second Law of Thermodynamics.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

 

Intro to Phase Separation

Ink and water mix but oil and water don’t. We all know this. But why? Mixing and demixing are relevant processes for many different systems: from the air, you breathe to metallic alloys on your car wheels, and to the smoothie on your breakfast. Recent research shows that these processes also take place inside cells! Biomolecules can be mixed with the liquid interior of the cell. Sometimes these molecules demix and form droplets like oil in water. A mechanism to assemble these droplets is assembled through a process called Phase Separation. This video is a short introduction to the physics of Phase Separation.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

Biomolecular Condensates

In schoolbooks, cells are generally pictured as a membrane bubble full of smaller compartments also wrapped by a membrane. In reality, things differ from this simple picture. There are many compartments that are not bound by a membrane. Learn what they are and their amazing properties in this 2 minute video!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

 

 

Centrosome Assembly

Hyman lab postdoc Jeff Woodruff describes the great unknowns of centrosome assembly and his plan of attack. Written and narrated by Jeff Woodruff. Produced by Lisa Dennison.

Phase Transition in Disease

In this video and the accompanying Cell paper, the Tony Hyman and Simon Alberti groups at Max Planck Institute propose an interesting idea that aging cells fail to maintain the liquid phase of ALS-associated protein FUS. The FUS liquid compartment instead forms disease-link solid phase aggregation.

Check out the paper at: http://www.cell.com/cell/abstract/S00….

Avinash Patel, Hyun O Lee, Louise Jawreth, Shovamayee Maharana, Marcus Jahnel, Marco Y. Hein, Stoyno Stoynov, Julia Mahamid, Shambaditya Saha, Titus M. Franzmann, et al. (2015). A Liquid to Solid Phase Transition of the ALS Protein FUS Correlates with Disease. Cell 162. And read more great research at http://www.cell.com/cell/home.

Phase Transitions in Cells

Hyman lab postdoc Louise Jawerth tackles the phase transitions that occur within the cytoplasm. Written and narrated by Louise Jawerth. Produced by Lisa Dennison.

Phase separation in cell polarity

In this video abstract, Shamba Saha tells you about his recent publication in Cell, “Polar Positioning of Phase-Separated Liquid Compartments in Cells Regulated by an mRNA Competition Mechanism.” Learn more in the full paper Saha et al. (2016) published in Cell, http://dx.doi.org/10.1016/j.cell.2016…

Written and narrated by Shamba Saha. Edited and produced by Lisa Dennison.

Regulation of centrosome assembly by phosphorylation

In this video abstract, Oliver Wueseke tells you about his recent publication in Biology Open, “Polo-like kinase phosphorylation determines C.elegans centrosome size and density by biasing SPD-5 toward an assembly-competent conformation,”

Learn more in the full paper Wueseke et al. (2016) http://dx.doi.org/10.1242/bio.020990

Written and narrated by Oliver Wueseke, illustrated by Jeff Woodruff, edited and produced by Lisa Dennison.

Building a synthetic centrosome

The centrosome is a structure in cells which is built every time the cell prepares to divide. In this video abstract, Jeff Woodruff explains how to build a centrosome in a test tube from purified proteins. He found that the centrosome acts like a sponge, which selectively soaks up the proteins needed to build microtubules.

Read more in the full paper, published in the journal Cell: http://www.cell.com/cell/fulltext/S00…

See the full blog post at: http://www.sciencesketches.org/single…

Jeff Woodruff is a postdoc in the lab of Tony Hyman (hymanlab.org) at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany

Microtubule nucleation through phase separation

Cells must build cytoskeleton structures, such as microtubules, where they are locally needed within the cell, but how do they do this? In this video abstract, Amayra Hernández-Vega explains that in a test tube, microtubules can be formed locally through phase separation. She also found that the protein Tau can phase separate into droplets, which can then concentrate enough tubulin to nucleate and build microtubules. Read more in the full paper, published in the journal Cell Reports: http://www.cell.com/cell-reports/abst… and see the full blog post at: http://www.sciencesketches.org/single…

Amayra Hernández-Vega is a postdoc in the lab of Tony Hyman (http://hymanlab.org) at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany.