Transglutaminase-mediated cross-linking of WDR54 regulates EGF receptor-signaling

Area of Science:

• Molecular Biology
• Oncology
• Biochemistry

Background:

• WDR54 is a novel oncogene in colorectal cancer.
• Its molecular mechanism and interactions are largely unknown.
• Understanding WDR54's function is crucial for cancer therapy.

Purpose of the Study:

• To elucidate the molecular mechanism of WDR54 in colorectal cancer.
• To investigate WDR54's interaction with transglutaminase 2 (TG2) and the EGF receptor signaling pathway.
• To explore the potential of targeting WDR54 post-translational modifications for cancer drug development.

Main Methods:

• In vitro cross-linking assays to study WDR54 modification by TG2.
• Site-directed mutagenesis to identify key residues in WDR54.
• Confocal microscopy to observe WDR54 and EGF receptor localization.
• Western blotting to assess Erk activity and EGF receptor ubiquitination.
• Genome editing to generate WDR54-deficient cells.

Main Results:

• WDR54 is cross-linked by TG2, requiring its carboxyl-terminal WD domain and Lysine 280 residue.
• Cross-linked WDR54 localizes to plasma membrane vesicles, sustaining EGF receptor activation and Erk signaling.
• Cells lacking WDR54 exhibit delayed growth.
• WDR54's mechanism involves enhancing EGF receptor-mediated signaling.

Conclusions:

• WDR54 functions as an oncogene by interacting with TG2 to enhance EGF receptor signaling and promote colorectal cancer cell proliferation.
• WDR54's post-translational modification by TG2 is a key mechanism driving tumor growth.
• Targeting WDR54 post-translational modifications presents a potential therapeutic strategy for colorectal cancer.