Induction of DUSP14 ubiquitination by PRMT5-mediated arginine methylation

Area of Science:

• Immunology
• Molecular Biology
• Biochemistry

Background:

• Dual-specificity phosphatase (DUSP)14 regulates T-cell receptor (TCR) signaling and immune responses.
• DUSP14 activity is modulated by TNF receptor associated factor (TRAF)2-mediated ubiquitination.
• The upstream regulatory mechanisms of DUSP14 activity remain incompletely understood.

Purpose of the Study:

• To investigate the interaction between DUSP14 and protein arginine methyltransferase (PRMT)5.
• To elucidate the role of PRMT5-mediated methylation in regulating DUSP14 function.
• To understand the impact of this regulatory pathway on TCR signaling.

Main Methods:

• Proximity ligation assay to detect protein interactions.
• Site-directed mutagenesis to create DUSP14 methylation mutants.
• Short hairpin RNA (shRNA) knockdown to assess PRMT5 function.
• Analysis of DUSP14 ubiquitination and phosphatase activity.

Main Results:

• DUSP14 directly interacts with PRMT5, which methylates DUSP14 at specific arginine residues.
• PRMT5-mediated methylation of DUSP14 is crucial for TRAF2-mediated ubiquitination and DUSP14 phosphatase activity.
• DUSP14 methylation, TRAF2 binding, and ubiquitination are reduced upon PRMT5 knockdown.
• DUSP14 interacts with and is methylated by PRMT5 during TCR signaling in T cells.

Conclusions:

• PRMT5-mediated arginine methylation of DUSP14 is a novel regulatory mechanism.
• This methylation sequentially promotes DUSP14 ubiquitination and phosphatase activity.
• The PRMT5-DUSP14 pathway inhibits TCR signaling and T-cell-mediated immune responses.