Toll-like receptors (TLRs) were the first pattern recognition receptors (PRRs) identified in mammals and to date are the best characterized. They initiate key inflammatory responses and also shape adaptative immunity. All TLRs (10 in humans and 11 in mice) are type I transmembrane proteins characterized by an extracellular leucine-rich domain and a cytoplasmic tail. They recognize diverse pathogen-associated molecular patterns ( PAMPs ) from bacteria, fungi, parasites and viruses, including lipid-based bacterial cell wall components such as lipopolysaccharide (LPS) and lipopeptides, microbial protein components such as flagellin, and nucleic acids such as single-stranded or double-stranded RNA and CpG DNA. They also react to certain damage-associated molecular patterns (DAMPs) from endogenous cells and the environment.
InvivoGen offers numerous tools to study TLR signaling pathways: TLR-expressing cell lines ; a comprehensive choice of TLR ligands (agonists and antagonists); TLR antibodies for detection or neutralization; TLR inhibitors such as signal transduction inhibitors and shRNAs; fully-sequenced TLR and related genes ; and TLR-detection products such as PRR signaling reporter plasmids.
Proteins can associate to form protein complexes , these often contain a set of proteins with similar functions, such as enzymes that carry out several steps in the same metabolic pathway.  This organization can allow substrate channeling , which is when the product of one enzyme is passed directly to the next enzyme in a pathway without being released into solution.  Channeling can make a pathway more rapid and efficient than it would be if the enzymes were randomly distributed in the cytosol, and can also prevent the release of unstable reaction intermediates.  Although a wide variety of metabolic pathways involve enzymes that are tightly bound to each other, others may involve more loosely associated complexes that are very difficult to study outside the cell.   Consequently, the importance of these complexes for metabolism in general remains unclear.
AIM2 is referred to as the DNA inflammasome for its ability to detect foreign dsDNA , using a HIN200 (hematopoietic interferon-inducible nuclear antigens with 200 amino acid repeats) domain (encoded by IFI16 ) attached to a PYD , which it uses to recruit the adaptor protein ASC during inflammasome formation.    AIM2 binds dsDNA with its C-terminal domain.    The PYDdomain of AIM2 homotypically interacts by PYD-PYD interactions with ASC . The ASC CARD domain recruits procaspase-1 into the complex. Caspase-1 activates maturation of proinflammatory cytokines ( IL-1b , IL-18 ). AIM2 is activated by viral dsDNA, bacterial dsDNA and also aberrant host dsDNA.   Activation of the AIM2 is supposed to play role in autoimmune responses during the autoimmune disease systematic lupus erythematosus . AIM2 inflammasome is also activated by pharmacological disruption of nuclear envelope integrity.