Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1
Reactive intermediates such as reactive nitrogen species play essential roles in the cell as signaling molecules but, in excess, constitute a major source of cellular damage. We found that nitrosative stress induced by steady-state nitric oxide (NO) caused rapid activation of an ATM damage-response...
| Main Authors: | , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
National Academy of Sciences (U.S.)
2014
|
| Online Access: | http://hdl.handle.net/1721.1/85913 https://orcid.org/0000-0003-0771-9889 |
| _version_ | 1826212467047399424 |
|---|---|
| author | Trudel, Laura J. Wogan, Gerald N. Tripathi, Durga N. Chowdhury, Rajdeep Tee, Andrew R. Slack, Rebecca S. Walker, Cheryl Lyn |
| author2 | Massachusetts Institute of Technology. Department of Biological Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Biological Engineering Trudel, Laura J. Wogan, Gerald N. Tripathi, Durga N. Chowdhury, Rajdeep Tee, Andrew R. Slack, Rebecca S. Walker, Cheryl Lyn |
| author_sort | Trudel, Laura J. |
| collection | MIT |
| description | Reactive intermediates such as reactive nitrogen species play essential roles in the cell as signaling molecules but, in excess, constitute a major source of cellular damage. We found that nitrosative stress induced by steady-state nitric oxide (NO) caused rapid activation of an ATM damage-response pathway leading to downstream signaling by this stress kinase to LKB1 and AMPK kinases, and activation of the TSC tumor suppressor. As a result, in an ATM-, LKB1-, TSC-dependent fashion, mTORC1 was repressed, as evidenced by decreased phosphorylation of S6K, 4E-BP1, and ULK1, direct targets of the mTORC1 kinase. Decreased ULK1 phosphorylation by mTORC1 at S757 and activation of AMPK to phosphorylate ULK1 at S317 in response to nitrosative stress resulted in increased autophagy: the LC3-II/LC3-I ratio increased as did GFP-LC3 puncta and acidic vesicles; p62 levels decreased in a lysosome-dependent manner, confirming an NO-induced increase in autophagic flux. Induction of autophagy by NO correlated with loss of cell viability, suggesting that, in this setting, autophagy was functioning primarily as a cytotoxic response to excess nitrosative stress. These data identify a nitrosative-stress signaling pathway that engages ATM and the LKB1 and TSC2 tumor suppressors to repress mTORC1 and regulate autophagy. As cancer cells are particularly sensitive to nitrosative stress, these data open another path for therapies capitalizing on the ability of reactive nitrogen species to induce autophagy-mediated cell death. |
| first_indexed | 2024-09-23T15:22:00Z |
| format | Article |
| id | mit-1721.1/85913 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:22:00Z |
| publishDate | 2014 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/859132022-10-02T02:27:58Z Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 Trudel, Laura J. Wogan, Gerald N. Tripathi, Durga N. Chowdhury, Rajdeep Tee, Andrew R. Slack, Rebecca S. Walker, Cheryl Lyn Massachusetts Institute of Technology. Department of Biological Engineering Trudel, Laura J. Wogan, Gerald N. Reactive intermediates such as reactive nitrogen species play essential roles in the cell as signaling molecules but, in excess, constitute a major source of cellular damage. We found that nitrosative stress induced by steady-state nitric oxide (NO) caused rapid activation of an ATM damage-response pathway leading to downstream signaling by this stress kinase to LKB1 and AMPK kinases, and activation of the TSC tumor suppressor. As a result, in an ATM-, LKB1-, TSC-dependent fashion, mTORC1 was repressed, as evidenced by decreased phosphorylation of S6K, 4E-BP1, and ULK1, direct targets of the mTORC1 kinase. Decreased ULK1 phosphorylation by mTORC1 at S757 and activation of AMPK to phosphorylate ULK1 at S317 in response to nitrosative stress resulted in increased autophagy: the LC3-II/LC3-I ratio increased as did GFP-LC3 puncta and acidic vesicles; p62 levels decreased in a lysosome-dependent manner, confirming an NO-induced increase in autophagic flux. Induction of autophagy by NO correlated with loss of cell viability, suggesting that, in this setting, autophagy was functioning primarily as a cytotoxic response to excess nitrosative stress. These data identify a nitrosative-stress signaling pathway that engages ATM and the LKB1 and TSC2 tumor suppressors to repress mTORC1 and regulate autophagy. As cancer cells are particularly sensitive to nitrosative stress, these data open another path for therapies capitalizing on the ability of reactive nitrogen species to induce autophagy-mediated cell death. National Institutes of Health (U.S.) (Grant RO1 CA143811) National Institutes of Health (U.S.) (Grant 5 P01 CA26731) National Institutes of Health (U.S.) (Grant ES002109) 2014-03-24T18:56:54Z 2014-03-24T18:56:54Z 2013-08 2013-03 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/85913 Tripathi, D. N., R. Chowdhury, L. J. Trudel, A. R. Tee, R. S. Slack, C. L. Walker, and G. N. Wogan. “Reactive Nitrogen Species Regulate Autophagy through ATM-AMPK-TSC2-Mediated Suppression of mTORC1.” Proceedings of the National Academy of Sciences 110, no. 32 (August 6, 2013): E2950–E2957. https://orcid.org/0000-0003-0771-9889 en_US http://dx.doi.org/10.1073/pnas.1307736110 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) National Academy of Science (U.S.) |
| spellingShingle | Trudel, Laura J. Wogan, Gerald N. Tripathi, Durga N. Chowdhury, Rajdeep Tee, Andrew R. Slack, Rebecca S. Walker, Cheryl Lyn Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 |
| title | Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 |
| title_full | Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 |
| title_fullStr | Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 |
| title_full_unstemmed | Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 |
| title_short | Reactive nitrogen species regulate autophagy through ATM-AMPK-TSC2-mediated suppression of mTORC1 |
| title_sort | reactive nitrogen species regulate autophagy through atm ampk tsc2 mediated suppression of mtorc1 |
| url | http://hdl.handle.net/1721.1/85913 https://orcid.org/0000-0003-0771-9889 |
| work_keys_str_mv | AT trudellauraj reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 AT wogangeraldn reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 AT tripathidurgan reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 AT chowdhuryrajdeep reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 AT teeandrewr reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 AT slackrebeccas reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 AT walkercheryllyn reactivenitrogenspeciesregulateautophagythroughatmampktsc2mediatedsuppressionofmtorc1 |