Analysis of state-space transitions identified potential triggers that might mediate exit from the stem cell state and highlighted a previously unrecognized inhibition of Fli1 by Gata1, which was subsequently validated experimentally.
Previous studies suggested that CCR7 down-regulation combined with S1P signaling mediate the exit of T cells from LNs for recirculation and immune responses [11], [32].
As the name implies, CKIs such as p21, p27 or p19 mediate the exit of the cell cycle through inhibition of cdk activity.
A recent study observed that mice with mutations in the Npc1 and Npc2 gene, which transcribe proteins that mediate the exit of lipoproteins from lysosomes, demonstrate striking retinal degeneration, upregulation of autophagy and marked lipofuscin accumulation within the RPE [ 18].
GLUT2 mediates the exit of monosaccharides from the enterocytes and SGLT1 and SGLT4 are responsible for the uptake of monosaccharide [ 35, 62, 63].
Iron exits the enterocyte through the efflux transporter ferroportin 1 (FPN), the only member of the SLC40 family of transporters and the first reported protein that mediates the exit of iron from cells [ 40].
In addition to promoting SC proliferation, cyclic AMP signaling also mediates the exit of SCs from the cell cycle by way of their transformation into a premyelinating phenotype [ 36].
In addition to its roles in pluripotency and self-renewal, FZD7 has been shown to have a role in mediating the exit of hESCs from a pluripotent state and their entry towards mesoderm specification induced by non-canonical Wnt signalling.
A combination of biochemical and immuno-EM approaches revealed that AP-3 mediates the exit of lysosomal membrane proteins from the early endosome-associated tubules, most likely for transport to late endosomes or lysosomes (dell'Angelica et al. 1998; Peden et al. 2004) (Fig. 3b).
Ablation of signals mediating exit from the ESC state during differentiation might also facilitate reprogramming.
