TAK1, but not TAB1 or TAB2, plays an essential role in multiple signaling pathways in vivo.

TGF-beta-activated kinase 1 (TAK1), a member of the MAPKKK family, is thought to be a key modulator of the inducible transcription factors NF-kappaB and AP-1 and, therefore, plays a crucial role in regulating the genes that mediate inflammation. Although in vitro biochemical studies have revealed the existence of a TAK1 complex, which includes TAK1 and the adapter proteins TAB1 and TAB2, it remains unclear which members of this complex are essential for signaling. To analyze the function of TAK1 in vivo, we have deleted the Tak1 gene in mice, with the resulting phenotype being early embryonic lethality.

A toll-like receptor that prevents infection by uropathogenic bacteria.

Toll-like receptors (TLRs) recognize molecular patterns displayed by microorganisms, and their subsequent activation leads to the transcription of appropriate host-defense genes. Here we report the cloning and characterization of a member of the mammalian TLR family, TLR11, that displays a distinct pattern of expression in macrophages and liver, kidney, and bladder epithelial cells. Cells expressing TLR11 fail to respond to known TLR ligands but instead respond specifically to uropathogenic bacteria.