TM184C Emerges as 7-Transmembrane Regulator of Autophagy and Intercellular Exchange
Updated
Updated · Nature.com · Sep 9
TM184C Emerges as 7-Transmembrane Regulator of Autophagy and Intercellular Exchange
3 articles · Updated · Nature.com · Sep 9
Summary
Scientists identified TM184C as a broadly expressed, evolutionarily ancient human protein that behaves like a GPCR-like regulator, controlling vesicle-driven material exchange between cells and restraining autophagy.
214 million AlphaFold2 models were mined to find structurally hidden seven-transmembrane proteins; TM184C stood out because it shows two hallmark GPCR activities—β-arrestin recruitment and GRK-dependent phosphorylation—despite lacking clear G-protein coupling.
TM184C localized not to the cell surface but to 500 nm-to-5 μm intracellular vesicles that move along microtubules, accumulate in cell projections and help form tunnelling nanotube-like and tumour microtube-like intercellular bridges.
CRISPR loss of TM184C disrupted projections, enlarged acidic vesicles and raised LC3B-II, while overexpression boosted bridge formation about threefold; intact C-terminal arrestin-code motifs were required for sustained connectivity and directional vesicle transfer.
The study also showed human TM184C rescued autophagic defects in yeast lacking its homologue Hfl1, suggesting an ancient conserved pathway and highlighting structure-based protein discovery as a way to uncover functions in the dark proteome.
Does this ancient intracellular protein rewrite the evolutionary history of how human cells communicate and manage internal waste?
Could an ancient, hidden protein discovered by AI hold the key to stopping cancer cells from sharing survival resources?
If AI can reveal superdark proteins missed by traditional science, what other fundamental biological secrets are hiding inside our cells?
TM184C and the Superdark Proteome: How AI Structural Biology Unveiled a Universal Regulator of Autophagy and Cellular Exchange
Overview
In 2026, scientists used AI-powered structural biology to discover TM184C, a 'superdark' protein hidden in the human genome. Unlike typical proteins, TM184C was found by comparing 3D shapes, not genetic sequences. This protein acts as a brake on autophagy and helps form tunneling nanotubes, which let cells share materials. Its unique signaling bypasses traditional pathways, instead recruiting arrestin and GPCR kinases. Targeting TM184C could help treat neurodegenerative diseases and cancer, but because it is widely present in the body, therapies must be carefully designed to avoid harmful side effects. This breakthrough shows how AI is opening new frontiers in drug discovery.