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Updated: Sep 10, 2025

siRNA Electroporation to Modulate Autophagy in Herpes Simplex Virus Type 1-Infected Monocyte-Derived Dendritic Cells
Published on: October 28, 2019
YTHDF proteins and m6A-RNA clients undergo autophagic turnover during contact inhibition
Hung Ho-Xuan1, Astrid Bruckmann2, Lautaro Natali3
1Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main 60438, Germany; Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main 60590, Germany; Regensburg Center for Biochemistry (RCB), Laboratory for RNA Biology, University of Regensburg, 93053 Regensburg, Germany.
Abstract:
The YTHDF protein family plays a critical role in cancer development by recognizing and regulating the stability of N6-methyladenosine (m6A)-modified RNA. Here, we reveal an autophagy-dependent mechanism controlling YTHDF protein levels. Using contact inhibition as a cellular model system, we show YTHDF proteins to be rapidly degraded, coinciding with increased autophagy and decreased mTOR activity. Upon pharmacological mTOR inhibition, YTHDF2 is also downregulated via lysosomal degradation. YTHDF2 selectively interacts with the autophagy modifier GABARAP L2 through LC3-interacting region (LIR) motifs in its unstructured N- and C-terminal regions. Autophagic YTHDF2 downregulation results in the co-degradation of its bound m6A-modified RNA clients. While YTHDF depletion induces cell death in contact-inhibition-deficient HCT116 cancer cells, contact-inhibited MRC5 and RPE1 cells remain unaffected. Our findings uncover a regulatory pathway that governs YTHDF protein stability with significant implications for cancer biology and cell fate determination and suggest the existence of an autophagy-mediated degradation pathway for m6A-modified RNA.
Insights
Autophagy degrades YTHDF proteins, impacting cancer cell fate. This process, linked to mTOR signaling, affects stability of N6-methyladenosine (m6A)-modified RNA, influencing cancer development.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- The YTHDF protein family is crucial for cancer progression by regulating N6-methyladenosine (m6A)-modified RNA stability.
- Understanding the regulation of YTHDF protein levels is key to deciphering their role in cancer.
Purpose of the Study:
- To investigate the mechanism controlling YTHDF protein stability.
- To explore the link between autophagy, YTHDF proteins, and cancer cell fate.
Main Methods:
- Utilized contact inhibition as a cellular model.
- Employed pharmacological inhibition of mTOR.
- Investigated protein-protein interactions using LC3-interacting region (LIR) motifs.
- Assessed cell death in different cancer cell lines.
Main Results:
- YTHDF proteins are rapidly degraded during contact inhibition, associated with increased autophagy and decreased mTOR activity.
- mTOR inhibition leads to YTHDF2 downregulation via lysosomal degradation.
- YTHDF2 interacts with GABARAP L2 through LIR motifs.
- Autophagic degradation of YTHDF2 causes co-degradation of bound m6A-modified RNA.
- YTHDF depletion induces cell death in contact-inhibition-deficient cancer cells but not in contact-inhibited cells.
Conclusions:
- Discovered an autophagy-dependent mechanism regulating YTHDF protein stability.
- This pathway has significant implications for cancer biology and cell fate determination.
- Proposed an autophagy-mediated degradation pathway for m6A-modified RNA.
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