Oliver Rocks

Oliver Rocks

@oliverrocks.bsky.social

Cell signaling in space and time | Rho GTPases | membrane biology | self-organisation | cytoskeleton | all kinds of 🔬 - Group leader @Charité Berlin

82 followers35 following10 posts

Oliver Rocks reposted

An evolutionarily conserved, short linear actin filament-binding motif (SFM), present in >100 proteins. Great collaboration with the Windhorst and Marlovits labs. Happy to have contributed, by using macrophage podosomes as a readout. Publication in Nat Cell Biol: www.nature.com/articles/s41...

Oliver Rocks reposted

Original image from 2011 of what I just had seen under the microscope when I ran into @oliverrocks.bsky.social’s office to show him. Turned out he’d observed this too, had no idea what it was either, but was just as stunned and curious as I was. This is how it all started... /1

Oliver Rocks@oliverrocks.bsky.social

Check out our new release on BioRxiv co-lead by @pm-mueller.bsky.social 👉 rb.gy/lnrizk special🙏 to Severine Kunz #MDC @leventallab.bsky.social @andimicroscopy.bsky.social @ewerslab.bsky.social and Kedar Narayan @NCI CCR VolumeEM Are the days of discovering new cellular structures over?? /1

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How do rods form? Solid domains exclude reticulon proteins, which require packing defects for membrane insertion. Their displacement inhibits ER tubulation, driving membrane flattening and multilayered wrapping into rods. 🦉The ER exploits membrane solidification to spatially organize proteins! /6

Implications? 🤔new conceptual framework for understanding ER compartmentalisation, the regulation of the sheet-tubule equilibrium, and organelle plasticity? 🤔homeoviscous mechanism - rods acting as a sink for solidifying lipids to buffer the ER against acute thermal or metabolic fluctuations? /7

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Rods form as a function of temperature and lipid composition: in standard cell culture typically <30°C but also in vivo at 37°C - in alveolar type II lung cells natively enriched in saturated lipids /4 🙏Melissa Mikolaj @ Kedar Narayan lab

Mammalian membranes are thought to universally avoid macroscopic solidification, as reduced fluidity impairs plasticity and protein function. Cells counter this via lipid unsaturation and cholesterol buffering. However, the ER is deliberately cholesterol-poor to maintain high-curvature membranes!/5

We show that - in mammalian cells and in vivo - saturated lipids in the #endoplasmic reticulum can demix into stable, micrometer-scale #solid-like domains. The resulting long-range orientational order in the membrane gives rise to cell-spanning, rigid tubular structures, we term #rods /2

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