Tag: Innate immunity

Protein formylation is a chemical modification involved in bacterial and mitochondrial protein synthesis, protein maturation, innate immunity, inflammation and cellular signaling.

Acute inflammation is a rapid, short-term response to injury or infection. Learn about its causes, symptoms, inflammatory cells, immune response, resolution, and role in healing.

The immune response is the body’s natural defense against infections and harmful substances. Learn about innate and adaptive immunity, immune cells, antibodies, and immune memory.

TRIM5α is a specialised antiviral ubiquitin ligase that recognises retroviral capsids, assembles K63‑linked ubiquitin chains and promotes autophagic degradation. Its tripartite motif and SPRY domain enable potent restriction of retroviruses, making TRIM5α a key factor in innate antiviral immunity and retroviral defence.

MDA5 is a cytosolic receptor that detects long viral double‑stranded RNA and activates MAVS‑dependent interferon signalling. Its ATP‑driven filament formation enables precise recognition of replicating RNA viruses, while LGP2 stabilises MDA5 filaments to ensure accurate antiviral responses.

LGP2 is a regulatory RNA sensor that modulates the activity of RIG‑I and MDA5 rather than directly activating antiviral signalling. By stabilising MDA5 filaments and fine‑tuning RIG‑I responses, LGP2 ensures precise detection of viral RNA and prevents harmful immune overactivation.

NAIP is a pattern‑recognition receptor that detects bacterial ligands such as flagellin and type III secretion system proteins. By recruiting NLRC4 to form the NAIP–NLRC4 inflammasome, NAIP activates caspase‑1, triggers pyroptosis and drives early innate immune defence against intracellular pathogens.

TRIM21 is a unique intracellular antibody receptor and RING finger ubiquitin ligase that neutralises antibody‑coated viruses inside the cytosol. Through its PRY/SPRY domain and tripartite motif, TRIM21 triggers rapid ubiquitin‑mediated degradation and activates antiviral signalling pathways. Its roles in immunity, autoimmunity and biotechnology make TRIM21 a key regulator of intracellular defence.

TRIM25 is a RING finger ubiquitin ligase that activates the antiviral sensor RIG‑I through K63‑linked ubiquitination. Its tripartite motif and PRY/SPRY domain enable precise regulation of innate immune signalling, interferon production and viral restriction. TRIM25 is targeted by multiple viruses, highlighting its importance as a frontline antiviral factor.

The TRIM family is a large group of single‑chain RING finger ubiquitin ligases that regulate innate immunity, antiviral defence, autophagy, transcription and protein quality control. Defined by their tripartite motif—RING, B‑box and coiled‑coil domains—TRIM proteins use diverse C‑terminal regions to achieve precise substrate specificity. Their roles in immunity, development and cancer make them key regulators of cellular homeostasis.

RNF115 (BCA2) is a dual RING/U‑box E3 ubiquitin ligase that regulates membrane trafficking, innate immunity and antiviral defence. By ubiquitinating BST‑2/Tetherin, Rab7‑associated endosomal proteins and EGFR, RNF115 influences receptor turnover, immune signalling and cancer progression, making it a key regulator of cellular homeostasis.

The immune system is the body’s defense network against infections and harmful substances. Learn about its major components, immune cells, types of immunity, antibodies, inflammation, and immune memory.