TRIM45 negatively regulates NF-κB-mediated transcription and suppresses cell proliferation

Area of Science:

• Molecular Biology
• Cell Signaling
• Cancer Research

Background:

• The nuclear factor kappa B (NF-κB) signaling pathway is crucial for immune responses, inflammation, and cell survival.
• NF-κB activation is tightly regulated by posttranslational modifications and the ubiquitin-proteasome system.
• Tripartite motif-containing (TRIM) proteins, including ubiquitin ligases, are involved in diverse cellular processes.

Purpose of the Study:

• To investigate the role of TRIM45 in regulating NF-κB transcriptional activity.
• To determine if TRIM45 influences cell growth.
• To elucidate TRIM45's function within the NF-κB signaling cascade.

Main Methods:

• Luciferase reporter assays were employed to measure NF-κB-mediated transcription.
• The effect of TRIM45 overexpression on TNFα-induced signaling was assessed.
• TRIM45 variants, including a RING domain-deficient mutant, were utilized to study functional domains.

Main Results:

• TRIM45 was found to negatively regulate tumor necrosis factor alpha (TNFα)-induced NF-κB transcription.
• A TRIM45 mutant lacking the RING domain retained its inhibitory activity on the NF-κB signal.
• Overexpression of TRIM45 led to the suppression of cell growth.

Conclusions:

• TRIM45 functions as a repressor of the NF-κB signaling pathway.
• TRIM45 plays a role in the regulation of cell growth.
• These findings highlight TRIM45 as a novel modulator of NF-κB-dependent processes.