Identification of full length bovine TLR1 and functional characterization of lipopeptide recognition by bovine TLR2/1 heterodimer.

Toll-like receptors (TLR) are highly conserved pattern recognition receptors of the innate immune system. Toll-like receptor 2 (TLR2) recognizes bacterial lipopeptides in a heterodimeric complex with TLR6 or TLR1, thereby discriminating between di- or triacylated lipopeptides, respectively. Previously, we found that HEK293 cells transfected with bovine TLR2 (boTLR2) were able to respond to diacylated lipopeptides but did not recognize triacylated lipopeptides, even after cotransfection with the so far published sequence of boTLR1.

Regulators of G-protein signalling are modulated by bacterial lipopeptides and lipopolysaccharide.

Regulators of G-protein signalling accelerate the GTPase activity of G(alpha) subunits, driving G proteins in their inactive GDP-bound form. This property defines them as GTPase activating proteins. Here the effect of different Toll-like receptor agonists on RGS1 and RGS2 expression in murine bone marrow-derived macrophages and J774 cells was analysed.

Heterodimerization of TLR2 with TLR1 or TLR6 expands the ligand spectrum but does not lead to differential signaling.

TLR are primary triggers of the innate immune system by recognizing various microorganisms through conserved pathogen-associated molecular patterns. TLR2 is the receptor for a functional recognition of bacterial lipopeptides (LP) and is up-regulated during various disorders such as chronic obstructive pulmonary disease and sepsis. This receptor is unique in its ability to form heteromers with TLR1 or TLR6 to mediate intracellular signaling.

The beta-N-acetylhexosaminidase of Entamoeba histolytica is composed of two homologous chains and has been localized to cytoplasmic granules.

We have purified a beta-N-acetylhexosaminidase from trophozoites of Entamoeba histolytica to homogeneity. In SDS-PAGE, the enzyme yielded a single protein band at an apparent M(r) of 64,000. The elution behaviour of the native enzyme upon molecular sieve chromatography corresponded to a molecular mass of approximately 132,000 suggesting that the enzyme is a dimer.