Non-T cell activation linker (NTAL) proteolytic cleavage as a terminator of activatory intracellular signals

Non–T Cell Activation Linker (NTAL)

A key molecule necessary for activation of T lymphocytes through their antigen-specific T cell receptor (TCR) is the transmembrane adaptor protein LAT (linker for activation of T cells). Upon TCR engagement, LAT becomes rapidly tyrosine phosphorylated and then serves as a scaffold organizing a multicomponent complex that is indispensable for induction of further downstream steps of the signalin...

Pre-B Cell Differentiation Linker (NTAL) Confers Inhibitory Effects on The N Terminus of the Non-T Cell Activation

Grb2 and the non-T cell activation linker NTAL constitute a Ca(2+)-regulating signal circuit in B lymphocytes.

Activation of the B cell antigen receptor triggers phosphorylation of cytoplasmic and transmembrane adaptor proteins such as SLP-65 and NTAL, respectively. Specific phosphoacceptor sites in SLP-65 serve as docking sites for Ca(2+)-mobilizing enzymes Btk and PLC-gamma2. Phosphorylated NTAL recruits the Grb2 linker, but downstream signaling cascades are unclear. We now show that receptor-induced ...

Non-T cell activation linker (NTAL) negatively regulates TREM-1/DAP12-induced inflammatory cytokine production in myeloid cells.

The engagement of triggering receptor expressed on myeloid cells 1 (TREM-1) on macrophages and neutrophils leads to TNF-alpha and IL-8 production and enhances inflammatory responses to microbial products. For signal transduction, TREM-1 couples to the ITAM-containing adapter DNAX activation protein of 12 kDa (DAP12). In general, ITAM-mediated signals lead to cell activation, although DAP12 was ...

Activation of C1r by proteolytic cleavage.

C1r was unable to cleave and activate proenzyme C1s unless first incubated at 37 degrees C in the absence of calcium before the addition of C1s. The acquisition of ability to activate C1s was associated with, and paralleled by, cleavage of each of the two noncovalently bonded 95,000 dalton chains of the molecule into disulfide linked subunits of 60,000 and 35,000 daltons, respectively. Thus, C1...