He et al. [20] found that after TLR4 was activated by its ligands, it induced immunosuppressive factors TGF-β, VEGF, and IL-8 production, which resulted in tumor cell resistance to TNF-α induced apoptosis and immune evasion of cancer cells.
On the other hand, the enzyme was highly activated by its activators NH4+, AMP and F2,6P [33].
To summarize these results, we found that the directed mutation of the trypsinogen surface charge led to an almost complete loss of trypsinogen autoactivation, while the enzyme could still be completely activated by its natural activation enzyme human enteropeptidase.
Like ubiquitin NEDD8 is initially activated by its E1 activation enzyme APPBP1/UBA3 and transferred to the catalytic cysteine of the E2 (UBE2M or UBE2F in the case of CUL5) (Lammer et al, 1998; Liakopoulos et al, 1998; Osaka et al, 1998; Duda et al, 2008; Huang et al, 2009).
It is activated by its natural ligand SDF-1α.
It is activated by its ligand, TNF- α, a cytokine involved principally in host defense to bacterial, parasitic and viral infections.
Calpain-1 is an approximately 80-kDa Ca2+-activated cysteine protease that is activated by its autolysis into 76- and 58-kDa fragments (Goll et al., 2003).
It is strongly activated by its agonist menthol and serves as a major cold and cooling transduction channel [7], [8].
When RhoA is activated by its guanine nucleotide exchange factor, RhoGEF2, it activates Rho Kinase, which directly phosphorylates key serine and threonine residues on MLC [10].
ERα activated by its agonist increased the transcriptional activity of ETS-1 and the expression of ETS-1 responsive genes MMP1/9.
Perhaps Allora & Calzadilla want us to stop and consider the history of Beethoven's music as it emanates from their wounded beast of a piano, activated by its put-upon occupant.
