SAMTOR Sensor Modulates mTORC1 via SAM Binding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway's regulation by amino acids is complex, and the role of methionine in inhibiting mTORC1 signaling is not fully understood, with existing knowledge lacking clarity on how methionine levels are sensed and translated into signaling outcomes.
Innovation Solution
The identification of SAMTOR as a protein that inhibits mTORC1 signaling by interacting with GATOR1, with S-adenosylmethionine (SAM) disrupting this interaction, allowing methionine to modulate mTORC1 activity through its binding capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the amino acid sensing pathway is made more complex to regulate mTORC1 signaling, then the precision of signaling regulation is improved, but the difficulty of understanding and manipulating the pathway increases
Solution Approach 1:
SAMTOR acts as an intermediary protein that specifically senses SAM levels and transmits this information to the mTORC1 pathway through interaction with GATOR1. This intermediary role simplifies the overall pathway by providing a dedicated sensing mechanism for methionine/SAM, rather than requiring the existing amino acid sensors to detect all amino acid types.
Solution Approach 2:
The invention introduces a new sensing parameter (SAM binding) to the mTORC1 regulatory pathway. SAMTOR's ability to bind SAM directly creates a new controllable parameter that regulates mTORC1 activity, allowing precise control through SAM levels without complicating the existing amino acid sensing mechanisms.
2Adaptability or versatility
If multiple amino acid sensors are used to regulate mTORC1, then the coverage of amino acid sensing is improved, but the difficulty of identifying specific sensing mechanisms increases
Solution Approach 1:
The invention segments the amino acid sensing function by creating a dedicated SAMTOR protein specifically for methionine/SAM sensing, separate from other amino acid sensors like Sestrin2 (leucine) and CASTOR1 (arginine). This segmentation makes it easier to identify and study specific sensing mechanisms without the confusion of multi-functional sensors.
Solution Approach 2:
SAMTOR serves as a specific intermediary that mediates the sensing of methionine/SAM levels and transmits this information to the mTORC1 pathway through GATOR1 interaction. This dedicated intermediary role clarifies the specific sensing mechanism for methionine, distinct from other amino acid sensing pathways.
3Productivity
If the interaction between SAMTOR and GATOR1 is disrupted by SAM binding, then the activation of mTORC1 signaling is improved, but the stability of the SAMTOR-GATOR1 complex decreases
Solution Approach 1:
The SAMTOR-GATOR1 complex exhibits dynamic stability regulated by SAM binding. In the absence of SAM, the complex is stable and inhibits mTORC1. When SAM binds to SAMTOR, it induces a conformational change or competitive binding event that disrupts the SAMTOR-GATOR1 interaction, dynamically switching the system from an inhibited state to an activated state.
Solution Approach 2:
The binding of SAM to SAMTOR changes the interaction parameter between SAMTOR and GATOR1. SAM acts as a molecular switch that alters the binding affinity or conformational state of SAMTOR, thereby controlling its interaction with GATOR1 and subsequently regulating mTORC1 activity based on cellular SAM levels.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
SAMTOR effectively links methionine levels to mTORC1 signaling, enabling precise regulation of cell growth and metabolism in response to environmental cues, and methods for modulating mTORC1 activity are provided through SAM binding assays and agent administration.
Implementation Method 1
SAM disrupts the SAMTOR-GATOR1 complex by binding directly to SAMTOR with a dissociation constant of approximately 7 μM
Data Source
AI summary
The invention relates to methods of identifying compounds that modulate mTORC1 activity in a cell by modulating the activity of SAMTOR, as well as to the use of such identified compounds in the modulation of mTORC1 and the treatment of diseases and conditions characterized by aberrant mTORC1 activity.