Human E3 Ubiquitin-Protein Ligase TRIM13

The gene TRIM13 (tripartite motif containing 13) encodes an E3 ubiquitin-protein ligase in humans. This protein is anchored in the endoplasmic reticulum (ER) membrane and is involved in ubiquitination of target proteins for degradation or signalling.

Image from GeneCards

In research contexts (for example cell biology, autophagy, cancer biology, innate immunity), TRIM13 is gaining attention for its roles in ER stress, autophagy regulation, immune signalling, and tumour suppression.

Exemple :

-TRIM13 belongs to the TRIM/RBCC family : it has an N-terminal RING finger domain (which confers E3 ubiquitin ligase activity), one or two B-box zinc finger motifs, a coiled-coil region, and a C-terminal transmembrane domain anchoring it to the ER membrane.

-According to UniProt (entry O60858) the transmembrane segment spans approx residues 317-337.

-Localisation : It's associated with the endoplasmic reticulum membrane, facing the cytosol.

- ER-Associated Degradation (ERAD) & Autophagy :

TRIM13 participates in ER-associated degradation (ERAD) of misfolded or unassembled proteins in the ER. It also initiates autophagy under ER stress conditions. For example, TRIM13 expression induced autophagy in HEK293 cells under tunicamycin-induced ER stress.

Image from ResearchGate : The article

-Innate immune regulation & STING pathway :

Recent work shows TRIM13 restrains the pathogenic-DNA-triggered inflammatory response by ubiquitinating the adaptor STING (stimulator of interferon genes) at Lys6, thereby decelerating ER exit and promoting ER-initiated degradation of STING.

Image from Nature : The article

-Tumour suppression / Cell cycle / Autophagy cross-talk :

TRIM13 has been reported to act as a tumour suppressor in lung adenocarcinoma : overexpression suppressed proliferation, increased apoptosis, induced autophagy via the KEAP1/NRF2 pathway, and ubiquitinated p62/SQSTM1. Gene-based analyses also link low TRIM13 expression to worse prognosis in some cancers.

Image from ScienceDirecte : The article

Lipid metabolism / atherosclerosis

More recently, TRIM13 was shown to reduce cholesterol efflux and increase oxidised LDL uptake leading to foam cell formation, implicating TRIM13 in atherosclerosis.

Image from ScienceDirecte : The article

1. The RING domain is essential for ubiquitin ligase activity. Deletion mutants lacking the RING or coiled-coil domains lose functional activity in autophagy induction or cell death regulation. ResearchGate
2. Under ER stress, TRIM13 promotes K63-linked polyubiquitination (not K48) of caspase-8. This ubiquitination is required for caspase-8 translocation to the autophagosome/lysosome and activation of the apoptotic cascade. NCBI
3. TRIM13 interacts with p62/SQSTM1 (an autophagy adaptor) and DFCP1 (omegasome marker), linking ubiquitination, autophagy and ER stress responses. Uniprot

For an investigator working in molecular biology, cell stress, autophagy, immunity or cancer research, TRIM13 is a meaningful target. Using the recombinant human TRIM13 product as mentioned above allows for :

1. In vitro biochemical assays of ubiquitin ligase activity (with defined substrate/target interactions).
2. Overexpression or binding studies in cell lines to dissect TRIM13 function in ER stress, autophagy initiation or immune pathways.
3. Use as a control reagent or standard in validation of TRIM13 pathways, e.g., p62/p62 ubiquitination, caspase-8 activation, STING regulation.
4. As a reagent for translational research when exploring TRIM13 as tumour suppressor, immune modulator or metabolic regulator.

Having a well-characterised reagent for TRIM13 thus supports robust experiments addressing mechanistic biology and may contribute to novel therapeutic insights.

1. Because TRIM13 is membrane-anchored, its cellular localisation (ER) is key. Ensure subcellular fractionation or microscopy confirms ER-localisation in overexpression or knock-down settings.
2. Ubiquitin ligase assays should include the RING domain intact protein and can compare mutants (ΔRING, ΔCC, ΔTM) to understand domain-specific effects. ResearchGate

1. Autophagy induction under ER stress may be monitored by LC3 puncta, p62 turnover, autophagosome/lysosome markers, in conjunction with TRIM13 modulation. MDPI

1. In immune signalling models, TRIM13 knock-out or knock-down may enhance STING-mediated cytokine production. ResearchGate

1. In cancer cell systems, measure proliferation, apoptosis, ROS/oxidative stress, as TRIM13 expression may switch cell fate towards autophagy and death. NCBI

TRIM13 is a multifaceted E3 ubiquitin ligase anchored in the ER that regulates key cellular processes including ER stress response, autophagy, immune signalling and tumour suppression. For researchers exploring these domains, the Recombinant Human E3 ubiquitin-protein ligase TRIM13 reagent is a high-value tool enabling mechanistic and translational studies.

The Product