RNF149

RNF149 is a membrane-anchored RING-domain E3 ubiquitin ligase that controls the abundance of diverse substrates by directing them to proteasomal degradation, thereby restraining inflammatory and interferon signaling while also promoting tumor cell proliferation (PMID:38989590, PMID:40245000). In macrophages, STAT1 activation induces RNF149 transcription, and RNF149 in turn ubiquitinates IFNGR1 to drive its degradation, forming a negative-feedback brake on type-II interferon signaling that limits inflammation after myocardial infarction (PMID:38989590). RNF149 dampens innate antiviral immunity through parallel mechanisms: it ubiquitinates IRF3 via K27- and K33-linked chains to reduce IFN-β production (PMID:40245000), and ubiquitinates JAK1 via K27- and K33-linked chains to suppress type-I IFN JAK-STAT signaling, facilitating viral immune evasion (PMID:42183758); it also negatively regulates LPS/TLR4 signaling by K29-linked ubiquitination and degradation of CD63 (PMID:39104473). In cancer contexts RNF149 degrades the AKT phosphatase PHLPP2 to activate PI3K/AKT signaling and confer cisplatin resistance (PMID:37658961), and acts on additional substrates including DNAJC25, DEK (cooperatively with RNF170 via K48 chains), and CDKN2C to support proliferation (PMID:37958377, PMID:40120540, PMID:42049330). Beyond signaling, RNF149 functions in pre-emptive ER-associated quality control by selectively binding and ubiquitinating non-translocated, mislocalized proteins (PMID:37031316). Its membrane topology positions an extracellular domain that can be exploited to ubiquitinate proximity-recruited membrane substrates (PMID:40609944).

1. 2022 Medium

   An early functional handle established that RNF149 has distinct domain-defined variants with different subcellular localizations and a role in cell proliferation, before any substrate was known.

   Evidence siRNA knockdown, EGFP-tagged construct imaging, and RT-PCR in rat/mouse gonocyte and germ-cell lines

   PMID:35634494

   Open questions at the time

   • No ubiquitination substrate identified
   • Functional readout limited to proliferation markers (PCNA) without mechanistic targets
2. 2023 Medium

   RNF149 was defined as a membrane-bound E3 ligase that selectively recognizes mislocalized, non-translocated proteins, placing it in the pre-emptive ER quality control pathway.

   Evidence Selective binding assays, association with known pEQC components, and loss-of-function showing increased ER translocation flux

   PMID:37031316

   Open questions at the time

   • Specific endogenous mislocalized substrates not enumerated
   • Mechanism of the localization switch during ER stress unresolved
3. 2023 Medium

   RNF149 was linked to oncogenic signaling by identifying PHLPP2 and DNAJC25 as degradation substrates, connecting its ligase activity to PI3K/AKT activation and tumor progression.

   Evidence Reciprocal co-IP, in vitro/in vivo knockdown and overexpression, AKT inhibitor rescue in esophageal carcinoma, and proteomic substrate profiling in HCC

   PMID:37658961 PMID:37958377

   Open questions at the time

   • Ubiquitin chain linkage types not characterized for these substrates
   • Single-lab findings without orthogonal substrate validation
4. 2024 High

   The discovery that STAT1 induces RNF149 to degrade IFNGR1 established RNF149 as a transcriptionally driven negative-feedback brake on interferon-gamma signaling in inflammation.

   Evidence IP/MS, genetic KO with bone marrow transplantation, macrophage-specific knockdown, and rescue by IFNGR1 deletion in a myocardial infarction model

   PMID:38989590

   Open questions at the time

   • Ubiquitin linkage type on IFNGR1 not defined
   • Direct RING-dependent in vitro ubiquitination of IFNGR1 not shown
5. 2024 Medium

   Identification of CD63 as a K29-linkage substrate extended RNF149's negative regulation to TLR4/LPS innate signaling in monocytes.

   Evidence Co-IP, confocal microscopy, site-specific K29 ubiquitin chain characterization, and knockdown functional assays

   PMID:39104473

   Open questions at the time

   • Physiological consequences in vivo not established
   • Single-lab characterization
6. 2025 High

   Mapping site-specific IRF3 ubiquitination (K27 at K409; K33 at K366/K409) showed RNF149 directly dampens antiviral IFN-β induction, defining a chain-type-resolved degradation mechanism.

   Evidence Co-IP, site-specific ubiquitination mutagenesis, proteasome inhibitor and IFN-β/viral replication assays

   PMID:40245000

   Open questions at the time

   • In vivo antiviral relevance not fully defined
   • Relationship between IRF3 and other innate substrates within one pathway unclear
7. 2025 Medium

   RNF149 was shown to cooperate with RNF170 in K48-linked degradation of DEK, linking it to suppression of RIPK1-PANoptosis in airway epithelium.

   Evidence Mass spectrometry, molecular docking, K48-linkage and site mapping (K349), siRNA, and an in vivo house dust mite asthma model

   PMID:40120540

   Open questions at the time

   • Division of labor between RNF149 and RNF170 not resolved
   • Direct in vitro ubiquitination reconstitution not reported
8. 2025 Medium

   Engagement of RNF149's extracellular domain by a bispecific nanobody (NbTAC) to degrade ROR1 demonstrated that RNF149 can ubiquitinate membrane substrates brought into proximity, validating it as a targetable surface ligase.

   Evidence Phage display nanobody discovery, bispecific NbTAC, and cell-based ROR1 degradation/proliferation assays in TNBC

   PMID:40609944

   Open questions at the time

   • Endogenous natural membrane substrates not defined by this approach
   • Mechanism of extracellular-domain-driven recruitment not structurally resolved
9. 2026 Medium

   Identification of JAK1 as a K27/K33-linkage substrate showed RNF149 suppresses type-I IFN JAK-STAT signaling, a mechanism exploited for viral immune evasion.

   Evidence Co-IP, knockout functional assays, K27/K33 linkage mapping, proteasome inhibitor, ISG and EMCV replication assays

   PMID:42183758

   Open questions at the time

   • Whether IRF3 and JAK1 regulation are coordinate or independent is unresolved
   • Single-lab characterization
10. 2026 Medium

    RNF149 was shown to ubiquitinate CDKN2C (p18) and modulate CDK-inhibitor response in head and neck carcinoma, extending its substrate range to a cell-cycle regulator.

    Evidence Proximity ligation assay, co-IP, knockdown, proliferation and cell cycle analyses, 3D culture

    PMID:42049330

    Open questions at the time

    • Ubiquitin chain linkage and degradation kinetics not characterized
    • Direct enzymatic ubiquitination not reconstituted

• How RNF149 selects among its many reported substrates and deploys distinct ubiquitin chain linkages (K27/K29/K33/K48) in a context-specific manner remains unresolved.
• No structural basis for substrate or linkage selectivity
• No unifying model linking ER quality control to signaling substrate regulation
• Adaptor/cofactor requirements for substrate recruitment unknown