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Evidence for a molecular link between the tuberous sclerosis complex and the Crumbs complex
Dominique Massey-Harroche1, Marie-Hélène Delgrossi, Lydie Lane-Guermonprez
1IDBML, CNRS UMR6216, Case 907, Faculté des Sciences de Luminy, 13288 Marseille cedex 09, France.
Human Molecular Genetics
|January 20, 2007
Summary
The Crumbs 3 complex directly interacts with tuberous sclerosis complex 2 (TSC2), a key protein in tuberous sclerosis. This interaction regulates the mTORC1 pathway, impacting cell metabolism and survival.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Mutations in TSC1/2 cause tuberous sclerosis, while CRB1 mutations lead to retinal degeneration.
- The Crumbs 3 (CRB 3) complex is involved in cell polarity and tissue organization.
- The mammalian Target Of Rapamycin Complex 1 (mTORC1) pathway regulates cell growth, metabolism, and survival.
Purpose of the Study:
- To investigate the molecular interaction between TSC2 and the CRB 3 complex.
- To determine the functional consequences of this interaction on the mTORC1 pathway.
Main Methods:
- Two-hybrid assay to detect protein-protein interactions.
- GST-pull down assays to confirm interactions with the CRB 3 complex.
- Co-immunoprecipitation and co-localization studies to assess interaction at tight junctions.
- Depletion of PATJ to evaluate its effect on mTORC1 activity.
Main Results:
- TSC2 directly interacts with PATJ, a component of the CRB 3 complex.
- TSC2 interacts with the entire CRB 3 complex and co-localizes with PATJ at tight junctions.
- Depletion of PATJ leads to increased mTORC1 activity, which is rapamycin-sensitive.
- Inhibition of PI-3K does not affect rpS6 phosphorylation, suggesting a specific role for the CRB complex in mTORC1 regulation.
Conclusions:
- The Crumbs 3 complex directly interacts with TSC1/2 proteins.
- This interaction serves as a potential regulator of the mTORC1 pathway, influencing cell metabolism and survival.
- Findings provide new insights into the molecular mechanisms underlying tuberous sclerosis and related disorders.
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