The role of the internal cavities on ligand binding pathways has been studied in mutants of HbI.
Two separate pathways of DNA damage, an oxidative pathway and a metal-binding pathway, have been proposed to account for the lesions observed in cell systems.
In plants, the conserved C-repeat binding factor (CBF) pathway has been associated to low temperature tolerance in a wide range of evolutionary distinct species [ 33].
Direct binding of C3 (the alternative pathway) has been proposed, although Xu et al showed recently that murine plasma contains natural IgM that can mediate opsonization of Ad5 for phagocytosis.
For example, the IRE1α-X-box-binding protein 1 (XBP-1) pathway has been shown to promote tumor growth in xenograft models (Romero-Ramirez et al, 2004) and loss of XBP-1 sensitized cells to death from oxidative stress (Liu et al, 2009).
The Yorkie homologues YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif, also known as WWTR1), effectors of the Hippo pathway, have been identified as mediators for mechanical stimuli1.
Although constitutive and ligand-independent activations of the EGFR pathway have been described, especially in the context of several cancers10, EGFR signaling depends mainly on the binding of a peptide growth factor of the EGF-family to an EGFR.
The regulation of NRF2 activity through additional noncanonical pathways has been identified: p62, which was discovered as an autophagy linker protein, induces NRF2 activation by competitive binding to the KEAP1 protein and autophagic degradation of KEAP129,30.
The activation of both PI3K/AKT pathway and ERK1/2 pathways has been previously related with neuroprotection effect31,32.
