González-Estévez, Cristina and Felix, Daniel A and Smith, Matthew D and Paps, Jordi and Morley, Simon J and James, Victoria and Sharp, Tyson V and Aboobaker, A Aziz (2012) SMG-1 and mTORC1 Act Antagonistically to Regulate Response to Injury and Growth in Planarians. PLoS Genetics, 8 (3). e1002619-e1002619. DOI https://doi.org/10.1371/journal.pgen.1002619
González-Estévez, Cristina and Felix, Daniel A and Smith, Matthew D and Paps, Jordi and Morley, Simon J and James, Victoria and Sharp, Tyson V and Aboobaker, A Aziz (2012) SMG-1 and mTORC1 Act Antagonistically to Regulate Response to Injury and Growth in Planarians. PLoS Genetics, 8 (3). e1002619-e1002619. DOI https://doi.org/10.1371/journal.pgen.1002619
González-Estévez, Cristina and Felix, Daniel A and Smith, Matthew D and Paps, Jordi and Morley, Simon J and James, Victoria and Sharp, Tyson V and Aboobaker, A Aziz (2012) SMG-1 and mTORC1 Act Antagonistically to Regulate Response to Injury and Growth in Planarians. PLoS Genetics, 8 (3). e1002619-e1002619. DOI https://doi.org/10.1371/journal.pgen.1002619
Abstract
Planarian flatworms are able to both regenerate their whole bodies and continuously adapt their size to nutrient status. Tight control of stem cell proliferation and differentiation during these processes is the key feature of planarian biology. Here we show that the planarian homolog of the phosphoinositide 3-kinase-related kinase (PIKK) family member SMG-1 and mTOR complex 1 components are required for this tight control. Loss of smg-1 results in a hyper-responsiveness to injury and growth and the formation of regenerative blastemas that remain undifferentiated and that lead to lethal ectopic outgrowths. Invasive stem cell hyper-proliferation, hyperplasia, hypertrophy, and differentiation defects are hallmarks of this uncontrolled growth. These data imply a previously unappreciated and novel physiological function for this PIKK family member. In contrast we found that planarian members of the mTOR complex 1, tor and raptor, are required for the initial response to injury and blastema formation. Double smg-1 RNAi experiments with tor or raptor show that abnormal growth requires mTOR signalling. We also found that the macrolide rapamycin, a natural compound inhibitor of mTORC1, is able to increase the survival rate of smg-1 RNAi animals by decreasing cell proliferation. Our findings support a model where Smg-1 acts as a novel regulator of both the response to injury and growth control mechanisms. Our data suggest the possibility that this may be by suppressing mTOR signalling. Characterisation of both the planarian mTORC1 signalling components and another PIKK family member as key regulators of regeneration and growth will influence future work on regeneration, growth control, and the development of anti-cancer therapies that target mTOR signalling. © 2012 Gonzalez-Estevez et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Item Type: | Article |
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Uncontrolled Keywords: | Stem Cells; Animals; Humans; Planarians; Sirolimus; Regeneration; Signal Transduction; Cell Differentiation; Cell Proliferation; RNA Interference; Molecular Sequence Data; Phosphatidylinositol 3-Kinases; TOR Serine-Threonine Kinases |
Subjects: | Q Science > QH Natural history > QH301 Biology Q Science > QH Natural history > QH426 Genetics |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 14 Oct 2015 10:51 |
Last Modified: | 07 Aug 2024 19:28 |
URI: | http://repository.essex.ac.uk/id/eprint/15095 |
Available files
Filename: 2012 Gonzalez-Estevez SMG1 and mTORC1 in planarians PLoS Genetics.pdf
Licence: Creative Commons: Attribution 3.0