Elucidating the interaction between MTDH, an oncoprotein with UPR signalling molecule IRE1α under cellular stress

Area of Science:

• Cellular Biology
• Molecular Oncology
• Signal Transduction

Background:

• Inositol-requiring enzyme type 1 alpha (IRE1α) is a crucial sensor for the unfolded protein response (UPR), detecting misfolded proteins in the endoplasmic reticulum (ER).
• IRE1α possesses kinase and endoribonuclease activities, managing cellular stress, with its C-terminal domain serving as a scaffold for regulatory proteins.
• Metadherin (MTDH), an oncoprotein, is known to promote cancer metastasis and survival by influencing various signaling pathways.

Purpose of the Study:

• To investigate the interaction between IRE1α and MTDH, a potential binding partner identified through mass spectrometry.
• To explore the implications of this interaction in the context of cellular stress response and cancer progression.
• To determine if a crosstalk exists between the homeostatic UPR pathway and metastatic signaling pathways involving IRE1α and MTDH.

Main Methods:

• Co-immunoprecipitation assays to confirm protein-protein interactions.
• Yeast-two hybrid assays for validating the interaction between IRE1α and MTDH.
• Bioinformatics analyses to support the interaction and explore functional implications.

Main Results:

• Experimental evidence confirmed a direct interaction between IRE1α and MTDH.
• The interaction suggests a functional link between the UPR pathway and MTDH-mediated cancer-promoting activities.
• This finding indicates a potential crosstalk between cellular homeostasis and metastatic signaling.

Conclusions:

• IRE1α and MTDH interact, suggesting a novel connection between ER stress response and cancer metastasis.
• This interaction may influence IRE1α's role in cellular stress, potentially explaining how cancer cells evade apoptosis.
• Further research into this crosstalk could reveal new therapeutic targets for cancer treatment.