Skip to Content

Search: {{$root.lsaSearchQuery.q}}, Page {{$root.page}}

RNA Diffusion Behavior Changes Under Hyperosmotic Phase Separation & Coupled Oscillators in Developmental Patterning and Growth

Guoming Gao & Usha Kadiyala
Friday, November 5, 2021
12:00-1:00 PM
1400 Chemistry Dow Lab Map
Proteins and RNAs can form functional biological condensates, also known as me braneless organelles, via liquid-liquid phase separation (LLPS). The partitioning of different proteins and RNAs between the dilute phase and the condensed phase provides delicate regulation over their functions, from promoting biochemical reactions and specific intermolecular interactions, to sequestering key molecules from downstream processing or signaling. Hyperosmotic phase separation (HOPS) is a recently discovered LLPS triggered by the hyperosmotic compression of cell volume. A majority of homo-multimeric proteins are shown to undergo HOPS in several cell types, including kidney cells that experience osmolarity fluctuations daily. Moreover, HOPS is much faster than most cellular LLPS processes (within ~10 s versus over minutes to hours), and thus HOPS condensates could be first responders sensing cell volume change and priming other stress responses. However, it was unclear whether RNAs contribute to HOPS and how HOPS impacts the diffusion behaviors and functions of different RNAs. Here, I used both fixed-cell super-resolution imaging and live-cell single molecule RNA tracking to quantify the interaction of mRNAs, lncRNAs, and miRNAs with HOPS condensates, and measure the change in their diffusion behaviors in the presence of HOPS. The preliminary results suggest that different RNAs have distinctive partitioning behaviors among HOPS condensates, and long-range active transport of RNAs are diminished under hyperosmotic conditions, presumably due to the compartmentalization by HOPS condensates.
&
Coordinated regulation of cell proliferation and differentiation is fundamental to the growth and patterning of multicellular structures. To understand how growth and patterning are coupled during vertebrate development, we designed both in-vivo and in-vitro systems to study the interactions between the cell cycle and the segmentation clock across different scales. We use a 3D zebrafish embryonic tissue model to demonstrate that the phase dynamics of the cell cycle and segmentation clock are spatially dependent. To further study the spatiotemporal dynamics of the two clocks, we designed a microfluidic oscillator device to show that fine tuning kinetic parameters allows control of morphogen gradients, laying preliminary work towards constructing an artificial segmentation clock
Building: Chemistry Dow Lab
Event Type: Workshop / Seminar
Tags: AEM Featured, Biophysics, Biophysics Program, seminar
Source: Happening @ Michigan from LSA Biophysics