# Salk Institute's light-controlled ASAP tool blocks autophagy in human cells within 5 minutes

- Published: 2026-11-14 08:39 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: autophagy inhibition, optogenetic tool, ASAP Salk Institute, nuclear pore complex, nucleoporins, LC3-interacting regions, P bodies, protein condensates, Nature Cell Biology, Christina Towers
- URL: https://realtech.media/news/rt-b900d5d2cec349cf86f3745a_salk_institute_s/

**Salk Institute researchers built ASAP, an optogenetic tool that blocks autophagy within 5 minutes of light in cultured human cells, and found nuclear pore proteins among its substrates.**

![Salk Institute's light-controlled ASAP tool blocks autophagy in human cells within 5 minutes](https://realtech.media/media/2026/11/d59354742ad48d21.jpg)
*Korinna, Wikimedia Commons, CC BY 4.0*

Biologists at the Salk Institute in La Jolla, led by Christina Towers, reported ASAP (Autophagic SNARE for Abrupt Photomanipulation), a light-controlled tool that inhibits autophagy in cells. The work was published in Nature Cell Biology on November 12, 2026, and was carried out on human cells in culture. According to the authors, autophagy is inhibited within 5 minutes of light exposure [1].

## How ASAP works

ASAP is an optogenetic tool: cells are engineered so that light controls a protein. The authors describe an approach based on light-induced proteolytic cleavage that selectively inhibits autophagy [1]. Towers says the team designed a protein that relocates after a small dose of light and blocks autophagy in a target cell, and that the tool is tunable and reversible.

Autophagy is a conserved recycling process that handles intracellular quality control [1]. Because the tool acts fast, proteins that accumulate immediately after the block mark the substrates that autophagy regulates most tightly. The team, together with David Gonzalez at UC San Diego, profiled the protein content of the cells from 5 to 60 minutes after inhibition [1].

## Nuclear pore proteins as substrates

The profiling confirmed many known autophagy substrates and revealed previously unidentified ones, including nuclear pore complex proteins [1]. Autophagy controls the quality of cytoplasmic complexes of nucleoporins through specific LC3-interacting regions, while sparing nuclear pore complex proteins embedded in the nuclear envelope [1]. The institute's press release adds that the targeted complexes are partially built ones, and that work with Maximiliano D'Angelo's lab at the Sanford Burnham Prebys Medical Discovery Institute identified the signal on the pores that autophagy recognizes.

When autophagy is rapidly inhibited, incomplete nucleoporin complexes accumulate. Instead of being degraded, the cytoplasmic nucleoporin complexes aggregate in processing bodies (P bodies) [1]. Within minutes of the block, the researchers also saw specific protein condensates, which regulate protein translation, build up in response to the accumulating nuclear pore proteins. The authors present this as a link between protein translation and autophagy.

Towers' group plans to apply ASAP to cancer cells to measure how fast their metabolism rewires once autophagy is blocked. Other research groups have approached the Salk team about using the tool, with particular interest in neurons.

## Sources

1. [Nature Cell Biology](https://doi.org/10.1038/s41556-026-02124-2)
2. [EurekAlert](https://www.eurekalert.org/news-releases/1150971)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b900d5d2cec349cf86f3745a_salk_institute_s/