Sterol biosensor reveals LAM-family Ltc1-dependent sterol flow to endosomes upon Arp2/3 inhibition.

Sterols are crucial components of biological membranes, which are synthetized in the ER and accumulate in the plasma membrane (PM). Here, by applying a genetically encoded sterol biosensor (D4H), we visualize a sterol flow between PM and endosomes in the fission yeast Schizosaccharomyces pombe. Using time-lapse and correlative light-electron microscopy, we found that inhibition of Arp2/3-dependent F-actin assembly promotes the reversible relocalization of D4H from the PM to internal sterol-rich compartments (STRIC) labeled by synaptobrevin Syb1. Retrograde sterol internalization to STRIC is independent of endocytosis or an intact Golgi, but depends on Ltc1, a LAM/StARkin-family protein localized to ER-PM contact sites. The PM in ltc1Δ cells over-accumulates sterols and upon Arp2/3 inhibition forms extended ER-interacting invaginations, indicating that sterol transfer contributes to PM size homeostasis. Anterograde sterol movement from STRIC is independent of canonical vesicular trafficking but requires Arp2/3, suggesting a novel role for this complex. Thus, transfer routes orthogonal to vesicular trafficking govern the flow of sterols in the cell

Reality beckons: metamodernist depthiness beyond panfictionality

It is often argued that postmodernism has been succeeded by a new dominant cultural logic. We conceive of this new logic as metamodernism. Whilst some twenty-first century texts still engage with and utilise postmodernist practices, they put these practices to new use. In this article, we investigate the metamodern usage of the typically postmodernist devices of metatextuality and ontological slippage in two genres: autofiction and true crime documentary. Specifically, we analyse Ruth Ozeki’s A Tale for the Time Being and the Netflix mini-series The Keepers, demonstrating that forms of fictionalisation, metafictionality and ontological blurring between fiction and reality have been repurposed. We argue that, rather than expand the scope of fiction, overriding reality, the metamodernist repurposing of postmodernist textual strategies generates a kind of ‘reality-effect’